Gas Enclosure Systems and Methods Utilizing Multi-Zone Circulation and Filtration

ABSTRACT

The present teachings relate to various embodiments of a gas enclosure system that can have a particle control system that can include a multi-zone gas circulation and filtration system, a low-particle-generating X-axis linear bearing system for moving a printhead assembly relative to a substrate, a service bundle housing exhaust system, and a printhead assembly exhaust system. Various components of a particle control system can include a tunnel circulation and filtration system that can be in flow communication with bridge circulation and filtration system. Various embodiments of a tunnel circulation and filtration system can provide cross-flow circulation and filtration of gas about a floatation table of a printing system. Various embodiments of a gas enclosure system can have a bridge circulation and filtration system that can provide circulation and filtration of gas about a printing system bridge and related apparatuses and devices. Accordingly, various embodiments of a gas circulation and filtration system as disclosed herein can effectively remove both airborne particulate matter, as well as particulate matter generated proximal to a substrate during a printing process. As such, various embodiments of a gas circulation and filtration system in conjunction with various embodiments of a gas purification system of the present teachings can provide for a controlled manufacturing environment resulting in a high-yield of OLED various devices.

CROSS REFERENCE TO RELATED CASES

This application is a continuation of U.S. application Ser. No.15/839,942, filed Dec. 13, 2017. U.S. application Ser. No. 15/839,942 isa continuation of U.S. application Ser. No. 15/046,381, filed Feb. 2,2017. U.S. application Ser. No. 15/046,381 is a continuation of Ser. No.14/801,653, filed Jul. 16, 2015. U.S. application Ser. No. 14/801,653claims benefit to U.S. Provisional Application No. 62/026,242, filedJul. 18, 2014 and to U.S. Provisional Application No. 62/034,718, filedAug. 7, 2014. All applications identified in this section areincorporated herein by reference; each in its entirety.

OVERVIEW

Interest in the potential of organic light-emitting diode (OLED) displaytechnology has been driven by OLED display technology attributes thatinclude demonstration of display panels that have highly saturatedcolors, are high-contrast, ultrathin, fast-responding, and energyefficient. Additionally, a variety of substrate materials, includingflexible polymeric materials, can be used in the fabrication of OLEDdisplay technology. Though the demonstration of displays for smallscreen applications, primarily for cell phones, has served to emphasizethe potential of the technology, challenges remain in scaling highvolume manufacturing across a range of substrate formats in high yield.

With respect to scaling of formats, a Gen 5.5 substrate has dimensionsof about 130 cm×150 cm and can yield about eight 26″ flat paneldisplays. In comparison, larger format substrates can include using Gen7.5 and Gen 8.5 mother glass substrate sizes. A Gen 7.5 mother glass hasdimensions of about 195 cm×225 cm, and can be cut into eight 42″ or six47″ flat panel displays per substrate. The mother glass used in Gen 8.5is approximately 220 cm×250 cm, and can be cut to six 55″ or eight 46″flat panel displays per substrate. One indication of the challenges thatremain in scaling of OLED display manufacturing to larger formats isthat the high-volume manufacture of OLED displays in high yield onsubstrates larger than Gen 5.5 substrates has proven to be substantiallychallenging.

In principle, an OLED device may be manufactured by the printing ofvarious organic thin films, as well as other materials, on a substrateusing an OLED printing system. Such organic materials can be susceptibleto damage by oxidation and other chemical processes. Housing an OLEDprinting system in a fashion that can be scaled for various substratesizes and can be done in an inert, substantially low-particle printingenvironment can present a variety of engineering challenges.Manufacturing tools for high throughput large-format substrate printing,for example, such as printing of Gen 7.5 and Gen 8.5 substrates, requiresubstantially large facilities. Accordingly, maintaining a largefacility under an inert atmosphere, requiring gas purification to removereactive atmospheric species, such as water vapor, oxygen and ozone, aswell as organic solvent vapors, as well as maintaining a substantiallylow-particle printing environment, has proven to be significantlychallenging.

As such, challenges remain in scaling high volume manufacturing of OLEDdisplay technology across a range of substrate formats in high yield.Accordingly, there exists a need for various embodiments a gas enclosuresystem of the present teachings that can house an OLED printing system,in an inert, substantially low-particle environment, and can be readilyscaled to provide for fabrication of OLED panels on a variety ofsubstrates sizes and substrate materials. Additionally, various gasenclosure systems of the present teachings can provide for ready accessto an OLED printing system from the exterior during processing and readyaccess to the interior for maintenance with minimal downtime.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the features and advantages of the presentdisclosure will be obtained by reference to the accompanying drawings,which are intended to illustrate, not limit, the present teachings.

FIG. 1A is a front perspective view of view of a gas enclosure assemblyin accordance with various embodiments of the present teachings. FIG. 1Bdepicts an exploded view of various embodiments of a gas enclosureassembly as depicted in FIG. 1A. FIG. 1C depicts an expanded isoperspective view of the printing system depicted in FIG. 1B.

FIG. 2 is an iso perspective view of the placement of substrate proximalto a printing area in a printing system equipped with a camera inaccordance with various embodiments of the present teachings.

FIG. 3A and FIG. 3B are schematic front cross-section views of variousembodiments of gas enclosure assembly and related system components ofthe present teachings.

FIG. 4 is an enlarged schematic front cross-section view of a portionindicated in FIG. 3B.

FIG. 5A is a schematic top section view of a gas enclosure system inaccordance with various embodiments of the present teachings. FIG. 5B isa long section schematic of view a gas enclosure system in accordancewith various embodiments of the present teachings.

FIG. 6 is a schematic front cross-section view of various embodiments ofgas enclosure assembly and related system components of the presentteachings.

FIG. 7A is a schematic top section view of a gas enclosure system inaccordance with various embodiments of the present teachings. FIG. 7B isa long section schematic of view a gas enclosure system in accordancewith various embodiments of the present teachings.

FIG. 8 is a schematic view of various embodiments of gas enclosureassembly and related system components the present teachings.

FIG. 9 is a schematic view of various embodiments of gas enclosureassembly and related system components the present teachings.

FIG. 10A and FIG. 10B are schematic views of various embodiments of gasenclosure assembly and related system components the present teachings.

FIG. 11A, FIG. 11B and FIG. 11C are schematic views of variousembodiments of gas enclosure assembly and related system components thepresent teachings.

FIG. 12 is a front perspective view of view of a gas enclosure assemblyin accordance with various embodiments of the present teachings.

FIG. 13A through FIG. 13D depicts the flow communication between apurification system and a gas enclosure system during various operationsin accordance with various embodiments of the present teachings.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present teachings disclose various embodiments of a gas enclosureassembly that can house, for example, an OLED printing system forprinting an OLED substrate. Various embodiments of a gas enclosureassembly can be sealably constructed and integrated with variouscomponents that provide a gas circulation and filtration system, aparticle control system, a gas purification system, and a thermalregulation system and the like to form various embodiments of a gasenclosure system with a controlled environment that can provide an inertgas environment that is substantially low-particle for processesrequiring such an environment. Various embodiments of a gas enclosurecan have a printing system enclosure and an auxiliary enclosureconstructed as a section of a gas enclosure assembly, which can besealably isolated from the printing system enclosure of a gas enclosure.

According to systems and methods of the present teachings, variousembodiments of a gas enclosure system can have a gas circulation andfiltration system in which gas can be circulated and filtered in variouszones. In various embodiments of gas enclosure systems and methods, agas circulation and filtration system can have a tunnel circulation andfiltration zone that provides, for example, but not limited by, across-flow of gas across a substrate support apparatus. According tosystems and methods of the present teachings, various embodiments of amulti-zone gas circulation and filtration system can have a printingsystem baffle assembly that is configured to circulate gas across asubstrate support apparatus to provide a cross-flow circulation paththat is across the direction of substrate travel. In various embodimentsof systems and methods of the present teachings, the cross-flow of gasacross a substrate support apparatus in a tunnel circulation andfiltration zone can be substantially laminar, thereby providing for alow-particle environment throughout a tunnel enclosure section.Additionally, for systems and methods of the present teachings, thecross flow of gas in a printing region proximal to a substrate canremove particles that may be generated by various printing systemdevices and apparatuses. As such, in addition to providing alow-particle environment throughout a tunnel enclosure section, thecross flow of gas in a printing region proximal to a substrate providesfor a low-particle environment in a printing area proximal to asubstrate.

Various embodiments of a multi-zone circulation and filtration system ofthe present teachings can have a bridge circulation and filtration zonethat can provide circulation and filtration of gas through a printingsystem bridge and related apparatuses and devices and away from asubstrate in a printing region. For various embodiments of a gasenclosure, a tunnel baffle plate can be used to direct gas flow throughan opening in the tunnel baffle plate that creates a transition-flowzone into a bridge circulation and filtration zone of gas enclosure. Assuch, the flow of gas from a transition-flow zone through a bridgecirculation and filtration zone provides for moving particles away froma substrate in a printing region, thereby providing for a low-particleprinting environment. Various embodiments of a multi-zone circulationand filtration system according to the present teachings can have abridge baffle plate and a bridge circulation and filtration outputplenum with a differ that can circulate gas about a printing systembridge and related apparatuses and devices. As such, the flow of gasfrom a bridge circulation and filtration output plenum through a bridgecirculation and filtration zone provides for moving particles away froma substrate in a printing region, thereby providing for a low-particleprinting environment.

Accordingly, various embodiments of a multi-zone gas circulation andfiltration system of the present teachings can effectively remove bothairborne particulate matter in various sections of a gas enclosure, aswell as particulate matter generated proximal to a substrate during aprinting process.

For clearer perspective regarding substrate sizes that can be used inmanufacturing of various OLED devises, generations of mother glasssubstrate sizes have been undergoing evolution for flat panel displaysfabricated by other-than OLED printing since about the early 1990's. Thefirst generation of mother glass substrates, designated as Gen 1, isapproximately 30 cm×40 cm, and therefore could produce a 15″ panel.Around the mid-1990's, the existing technology for producing flat paneldisplays had evolved to a mother glass substrate size of Gen 3.5, whichhas dimensions of about 60 cm×72 cm. In comparison, a Gen 5.5 substratehas dimensions of about 130 cm×150 cm.

As generations have advanced, mother glass sizes for Gen 7.5 and Gen 8.5are in production for other-than OLED printing fabrication processes. AGen 7.5 mother glass has dimensions of about 195 cm×225 cm, and can becut into eight 42″ or six 47″ flat panels per substrate. The motherglass used in Gen 8.5 is approximately 220×250 cm, and can be cut to six55″ or eight 46″ flat panels per substrate. The promise of OLED flatpanel display for qualities such as truer color, higher contrast,thinness, flexibility, transparency, and energy efficiency have beenrealized, at the same time that OLED manufacturing is practicallylimited to G 3.5 and smaller. Currently, OLED printing is believed to bethe optimal manufacturing technology to break this limitation and enableOLED panel manufacturing for not only mother glass sizes of Gen 3.5 andsmaller, but at the largest mother glass sizes, such as Gen 5.5, Gen7.5, and Gen 8.5. One of the features of OLED panel display technologyincludes that a variety of substrate materials can be used, for example,but not limited by, a variety of glass substrate materials, as well as avariety of polymeric substrate materials. In that regard, sizes recitedfrom the terminology arising from the use of glass-based substrates canbe applied to substrates of any material suitable for use in OLEDprinting.

Manufacturing tools that in principle can allow for the printing of avariety of substrate sizes that includes large-format substrate sizes,can require substantially large facilities for housing such OLEDmanufacturing tools. Accordingly, maintaining an entire large facilityunder an inert atmosphere presents engineering challenges, such ascontinual purification of a large volume of an inert gas. Variousembodiments of a gas enclosure system can have a circulation andfiltration system internal a gas enclosure assembly in conjunction witha gas purification system external a gas enclosure that together canprovide continuous circulation of a substantially low-particulate inertgas having substantially low levels of reactive species throughout a gasenclosure system. According to the present teachings, an inert gas maybe any gas that does not undergo a chemical reaction under a defined setof conditions. Some commonly used non-limiting examples of an inert gascan include nitrogen, any of the noble gases, and any combinationthereof. Additionally, providing a large facility that is essentiallyhermetically sealed to prevent contamination of various reactiveatmospheric gases, such as water vapor, oxygen and ozone, as well asorganic solvent vapors generated from various printing process poses anengineering challenge. According to the present teachings, an OLEDprinting facility would maintain levels for each species of variousreactive species, including various reactive atmospheric gases, such aswater vapor, oxygen and ozone, as well as organic solvent vapors at 100ppm or lower, for example, at 10 ppm or lower, at 1.0 ppm or lower, orat 0.1 ppm or lower.

The need for printing an OLED panel in a facility in which the levels ofeach of a reactive species should be maintained at targeted low levelscan be illustrated in reviewing the information summarized in Table 1.The data summarized on Table 1 resulted from the testing of each of atest coupon comprising organic thin film compositions for each of red,green, and blue, fabricated in a large-pixel, spin-coated device format.Such test coupons are substantially easier to fabricate and test for thepurpose of rapid evaluation of various formulations and processes.Though test coupon testing should not be confused with lifetime testingof a printed panel, it can be indicative of the impact of variousformulations and processes on lifetime. The results shown in the tablebelow represent variation in the process step in the fabrication of testcoupons in which only the spin-coating environment varied for testcoupons fabricated in a nitrogen environment where reactive species wereless than 1 ppm compared to test coupons similarly fabricated but in airinstead of a nitrogen environment.

It is evident through the inspection of the data in Table 1 shown belowfor test coupons fabricated under different processing environments,particularly in the case of red and blue, that printing in anenvironment that effectively reduces exposure of organic thin filmcompositions to reactive species may have a substantial impact on thestability of various ELs, and hence on lifetime. The lifetimespecification is of particular significance for OLED panel technology,as this correlates directly to display product longevity; a productspecification for all panel technologies, which has been challenging forOLED panel technology to meet. In order to provide panels meetingrequisite lifetime specifications, levels of each of a reactive species,such as water vapor, oxygen, and ozone, as well as organic solventvapors, can be maintained at 100 ppm or lower, for example, at 10 ppm orlower, at 1.0 ppm or lower, or at 0.1 ppm or lower with variousembodiments of a gas enclosure system of the present teachings.

TABLE 1 Impact of inert gas processing on lifetime for OLED panelsProcess V Cd/A CIE (x, y) T95 T80 T50 Color Environment @ 10 mA/cm² @1000 Cd/m² Red Nitrogen 6 9 (0.61, 0.38) 200 1750 10400 Air 6 8 (0.60,0.39) 30 700 5600 Green Nitrogen 7 66 (0.32, 0.63) 250 3700 32000 Air 761 (0.32, 0.62) 250 2450 19700 Blue Nitrogen 4 5 (0.14, 0.10) 150 7503200 Air 4 5 (0.14, 0.10) 15 250 1800

In addition to providing an inert environment, maintaining asubstantially low-particle environment for OLED printing is ofparticular importance, as even very small particles can lead to avisible defect on an OLED panel. Particle control in a gas enclosuresystem can present significant challenges not presented for processesthat can be done, for example, in atmospheric conditions under open air,high flow laminar flow filtration hoods. For example, of a manufacturingfacility can require a substantial length of various service bundlesthat can be operatively connected from various systems and assemblies toprovide optical, electrical, mechanical, and fluidic connectionsrequired to operate, for example, but not limited by, a printing system.Such service bundles used in the operation of a printing system andlocated proximal to a substrate positioned for printing can be anongoing source of particulate matter. Additionally, components used in aprinting system, such as fans or linear motion systems that use frictionbearing, can be particle generating components. Various embodiments of agas circulation and filtration system of the present teachings can beused in conjunction with particle control components to contain andexhaust particulate matter. Additionally, by using a variety ofintrinsically low-particle generating pneumatically operated components,such as, but not limited by, substrate floatation tables, air bearings,and pneumatically operated robots, and the like, a low particleenvironment for various embodiments of a gas enclosure system can bemaintained.

Regarding maintaining a substantially low-particle environment, variousembodiments of a multi-zone gas circulation and filtration system can bedesigned to provide a low particle inert gas environment for airborneparticulates meeting the standards of International StandardsOrganization Standard (ISO) 14644-1:1999, “Cleanrooms and associatedcontrolled environments-Part 1: Classification of air cleanliness,” asspecified by Class 1 through Class 5. However, controlling airborneparticulate matter alone is not sufficient for providing a low-particleenvironment proximal to a substrate during, for example, but not limitedby, a printing process, as particles generated proximal to a substrateduring such a process can accumulate on a substrate surface before theycan be swept through a gas circulation and filtration system.

Accordingly, in conjunction with a gas circulation and filtrationsystem, various embodiments of a gas enclosure system of the presentteachings can have a particle control system that can include componentsthat can provide a low-particle zone proximal to a substrate duringprocessing in a printing step. A particle control system for variousembodiments of a gas enclosure system of the present teachings caninclude a multi-zone gas circulation and filtration system, alow-particle-generating X-axis linear bearing system for moving aprinthead assembly relative to a substrate, a service bundle housingexhaust system, and a printhead assembly exhaust system. For example, agas enclosure system can have a gas circulation and filtration systeminternal a gas enclosure assembly.

For systems and methods of the present teachings, various embodiments ofa gas enclosure can have gas circulation and filtration in variouszones. For example, a tunnel circulation zone of a gas enclosure canprovide for the circulation of gas across a substrate support apparatusin a tunnel circulation and filtration zone to provide a cross-flowcirculation path that is across the direction of substrate travel. Invarious embodiments of systems and methods of the present teachings, thecross-flow of gas across a substrate support apparatus in a tunnelcirculation zone of a gas enclosure can be substantially laminar. Gasenclosure having a tunnel circulation zone can have a transition-flowzone proximal to a carriage assembly that draws gas away from asubstrate located below the carriage assembly. Various embodiments of agas enclosure system can have a bridge circulation and filtration zonethat can provide circulation and filtration of gas about a printingsystem bridge and related apparatuses and devices, and is in flowcommunication with the transition-flow zone. Such internal filtrationsystems can have a plurality of fans for circulation of air, where eachfan can be in serial flow communication with a heat exchanger forthermal control of the gas and a filtration unit providing control ofcirculating particulate matter. For various embodiments of a gasenclosure system, fan filter units can be used to circulate and filtergas, and a heat exchanger can be in flow communication with each fanfilter unit. Although a flow of gas generated by a circulation andfiltration system need not be laminar, a laminar flow of gas can be usedto ensure thorough and complete turnover of gas in the interior. Alaminar flow of gas can also be used to minimize turbulence, suchturbulence being undesirable as it can cause particles in theenvironment to collect in such areas of turbulence, preventing thefiltration system from removing those particles from the environment.

Various embodiments of systems and methods of the present teachings canmaintain a substantially low-particle environment providing for anaverage on-substrate distribution of particles of a particular sizerange of interest that does not exceed an on-substrate deposition ratespecification. An on-substrate deposition rate specification can be setfor each of a particle size range of interest of between about 0.1 μmand greater to about 10 μm and greater. In various embodiments systemsand methods of the present teachings, an on-substrate particledeposition rate specification can be expressed as a limit of the numberof particles deposited per square meter of substrate per minute for eachof a target particle size range.

Various embodiments of an on-substrate particle deposition ratespecification can be readily converted from a limit of the number ofparticles deposited per square meter of substrate per minute to a limitof the number of particles deposited per substrate per minute for eachof a target particle size range. Such a conversion can be readily donethrough a known relationship between substrates, for example, of aspecific generation-sized substrate and the corresponding area for thatsubstrate generation. For example, Table 2 below summarizes aspectratios and areas for some known generation-sized substrates. It shouldbe understood that a slight variation of aspect ratio and hence size maybe seen from manufacturer to manufacturer. However, regardless of suchvariation, a conversion factor for a specific generation-sized substrateand an area in square meters can be obtained any of a variety ofgeneration-sized substrates.

TABLE 2 Correlation between area and substrate size Generation ID X (mm)Y (mm) Area (m2) Gen 3.0 550 650 0.36 Gen 3.5 610 720 0.44 Gen 3.5 620750 0.47 Gen 4 680 880 0.60 Gen 4 730 920 0.67 Gen 5 1100 1250 1.38 Gen5 1100 1300 1.43 Gen 5.5 1300 1500 1.95 Gen 6 1500 1850 2.78 Gen 7.51950 2250 4.39 Gen 8 2160 2400 5.18 Gen 8 2160 2460 5.31 Gen 8.5 22002500 5.50 Gen 9 2400 2800 6.72 Gen 10 2850 3050 8.69

Additionally, an on-substrate particle deposition rate specificationexpressed as a limit of the number of particles deposited per squaremeter of substrate per minute can be readily converted to any of avariety of unit time expressions. It will be readily understood that anon-substrate particle deposition rate specification normalized tominutes can be readily converted to any other expression of time throughknow relationships of time, for example, but not limited by, such assecond, hour, day, etc. Additionally, units of time specificallyrelating to processing can be used. For example, a print cycle can beassociated with a unit of time. For various embodiments of a gasenclosure system according to the present teachings a print cycle can bea period of time in which a substrate is moved into a gas enclosuresystem for printing and then removed from a gas enclosure system afterprinting is complete. For various embodiments of a gas enclosure systemaccording to the present teachings a print cycle can be a period of timefrom the initiation of the alignment of a substrate with respect to aprinthead assembly to the delivery of a last ejected drop of ink ontothe substrate. In the art of processing, total average cycle time orTACT can be an expression of a unit of time for a particular processcycle. According to various embodiments of systems and methods of thepresent teachings, TACT for a print cycle can be about 30 seconds. Forvarious embodiments of systems and methods of the present teachings,TACT for a print cycle can be about 60 seconds. In various embodimentsof systems and methods of the present teachings, TACT for a print cyclecan be about 90 seconds. For various embodiments of systems and methodsof the present teachings, TACT for a print cycle can be about 120seconds. In various embodiments of systems and methods of the presentteachings, TACT for a print cycle can be about 300 seconds.

With respect to airborne particulate matter and particle depositionwithin a system, a substantial number of variables can impact developinga general model that may adequately compute, for example, anapproximation of a value for particle fallout rate on a surface, such asa substrate, for any particular manufacturing system. Variables such asthe size of particles, the distribution of particles of particular size;surface area of a substrate and the time of exposure of a substratewithin a system can vary depending on various manufacturing systems. Forexample, the size of particles and the distribution of particles ofparticular size can be substantially impacted by the source and locationof particle-generating components in various manufacturing systems.Calculations based on various embodiments of gas enclosure systems ofthe present teachings suggest that without various particle controlsystems of the present teachings, on-substrate deposition of particulatematter per print cycle per square meter of substrate can be between morethan about 1 million to more than about 10 million particles forparticles in a size range of 0.1 μm and greater. Such calculationssuggest that that without various particle control systems of thepresent teachings, on-substrate deposition of particulate matter perprint cycle per square meter of substrate can be between more than about1000 to about more than about 10,000 particles for particles in a sizerange of about 2 μm and greater.

Various embodiments of a low-particle gas enclosure system of thepresent teachings can maintain a low-particle environment providing foran average on-substrate particle distribution that meets an on-substratedeposition rate specification of less than or equal to about 100particles per square meter of substrate per minute for particles greaterthan or equal to 10 μm in size. Various embodiments of a low-particlegas enclosure system of the present teachings can maintain alow-particle environment providing for an average on-substrate particledistribution that meets an on-substrate deposition rate specification ofless than or equal to about 100 particles per square meter of substrateper minute for particles greater than or equal to 5 μm in size. Invarious embodiments of a gas enclosure system of the present teachings,a low-particle environment can be maintained providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 100 particles persquare meter of substrate per minute for particles greater than or equalto 2 μm in size. In various embodiments of a gas enclosure system of thepresent teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 100 particles per square meter of substrate per minute forparticles greater than or equal to 1 μm in size. Various embodiments ofa low-particle gas enclosure system of the present teachings canmaintain a low-particle environment providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 1000 particles persquare meter of substrate per minute for particles greater than or equalto 0.5 μm in size. For various embodiments of a gas enclosure system ofthe present teachings, a low-particle environment can be maintainedproviding for an average on-substrate particle distribution that meetsan on-substrate deposition rate specification of less than or equal toabout 1000 particles per square meter of substrate per minute forparticles greater than or equal to 0.3 μm in size. Various embodimentsof a low-particle gas enclosure system of the present teachings canmaintain a low-particle environment providing for an averageon-substrate particle distribution that meets an on-substrate depositionrate specification of less than or equal to about 1000 particles persquare meter of substrate per minute for particles greater than or equalto 0.1 μm in size.

It is contemplated that a wide variety of ink formulations can beprinted within the inert, substantially low-particle environment ofvarious embodiments of a gas enclosure system of the present teachings.During the manufacture of an OLED display, an OLED pixel can be formedto include an OLED film stack, which can emit light of a specific peakwavelength when a voltage is applied. An OLED film stack structurebetween an anode and a cathode can include a hole injection layer (HIL),a hole transport layer (HTL), an emissive layer (EL), an electrontransport layer (ETL) and an electron injection layer (EIL). In someembodiments of an OLED film stack structure, an electron transport layer(ETL) can be combined with an electron injection layer (EIL) to form anETL/EIL layer. According to the present teachings, various inkformulations for an EL for various color pixel EL films of an OLED filmstack can be printed using inkjet printing. Additionally, for example,but not limited by, the HIL, HTL, EML, and ETL/EIL layers can have inkformulations that can be printed using inkjet printing.

It is further contemplated that an organic encapsulation layer can beprinted on an OLED panel using inkjet printing. It is contemplated thatan organic encapsulation layer can be printed using inkjet printing, asinkjet printing can provide several advantages. First, a range of vacuumprocessing operations can be eliminated because such inkjet-basedfabrication can be performed at atmospheric pressure. Additionally,during an inkjet printing process, an organic encapsulation layer can belocalized to cover portions of an OLED substrate over and proximal to anactive region, to effectively encapsulate an active region, includinglateral edges of the active region. The targeted patterning using inkjetprinting results in eliminating material waste, as well as eliminatingadditional processing typically required to achieve patterning of anorganic layer. An encapsulation ink can comprise a polymer including,for example, but not limited by, an acrylate, methacrylate, urethane, orother material, as well as copolymers and mixtures thereof, which can becured using thermal processing (e.g. bake), UV exposure, andcombinations thereof. As used herein polymer and copolymer can includeany form of a polymer component that can be formulated into an ink andcured on a substrate to form an organic encapsulation layer. Suchpolymeric components can include polymers, and copolymers, as well asprecursors thereof, for example, but not limited by, monomers,oligomers, and resins.

Various embodiments of a gas enclosure assembly can have various framemembers that are constructed to provide contour for a gas enclosureassembly. Various embodiments of a gas enclosure assembly of the presentteachings can accommodate an OLED printing system, while optimizing theworking space to minimize inert gas volume, and also allowing readyaccess to an OLED printing system from the exterior during processing.In that regard, various gas enclosure assemblies of the presentteachings can have a contoured topology and volume. As will be discussedin more detail subsequently herein, various embodiments of a gasenclosure can be contoured around a printing system base, upon which asubstrate support apparatus can be mounted. Further, a gas enclosure canbe contoured around a bridge structure used for the X-axis movement of acarriage assembly. As a non-limiting example, various embodiments of acontoured gas enclosure according to the present teachings can have agas enclosure volume of between about 6 m³ to about 95 m³ for housingvarious embodiments of a printing system capable of printing substratesizes from Gen 3.5 to Gen 10. By way a further non-limiting example,various embodiments of a contoured gas enclosure according to thepresent teachings can have a gas enclosure volume of between about 15 m³to about 30 m³ for housing various embodiments of a printing systemcapable of printing, for example, Gen 5.5 to Gen 8.5 substrate sizes.Such embodiments of a contoured gas enclosure can be between about 30%to about 70% savings in volume in comparison to a non-contouredenclosure having non-contoured dimensions for width, length and height.

FIG. 1A depicts a perspective view of contoured gas enclosure assembly1000 in accordance with various embodiments of a gas enclosure assemblyof the present teachings. Gas enclosure assembly 1000 can include frontpanel assembly 1200, middle panel assembly 1300 and rear panel assembly1400. Front panel assembly 1200 can include front ceiling panel assembly1260, front wall panel assembly 1240, which can have opening 1242 forreceiving a substrate, and front base panel assembly 1220. Front panelassembly 1200 when assembled can provide a first tunnel enclosuresection of a gas enclosure, which is supported by a base. Rear panelassembly 1400 can include rear ceiling panel assembly 1460, rear wallpanel assembly 1440, which can have opening 1442 for removing asubstrate, and rear base panel assembly 1420. Rear panel assembly 1400when assembled can provide a second tunnel enclosure section of a gasenclosure, which is supported by a base. Middle panel assembly 1300 caninclude first middle enclosure panel assembly 1340, middle wall andceiling panel assembly 1360 and second middle enclosure panel assembly1380, as well as middle base panel assembly 1320. Middle panel assembly1300 when assembled can provide a bridge enclosure section of a gasenclosure, which is supported by a base.

Additionally, as depicted in FIG. 1A, middle panel assembly 1300 caninclude first printhead management system substantially low particleenvironment, as well as a second printhead management system auxiliarypanel assembly (not shown), which provides for an auxiliary gasenclosure. Various embodiments of an auxiliary enclosure constructed asa section of a gas enclosure assembly can be sealably isolated from theworking volume of a gas enclosure system. For various embodiments ofsystems and methods of the present teachings, an auxiliary enclosure canbe less than or equal to about 1% of the enclosure volume of a gasenclosure system. In various embodiments of systems and methods of thepresent teachings, an auxiliary enclosure can be can be less than orequal to about 2% of the enclosure volume of a gas enclosure system. Forvarious embodiments of systems and methods of the present teachings, anauxiliary enclosure can be less than or equal to about 5% of theenclosure volume of a gas enclosure system. In various embodiments ofsystems and methods of the present teachings, an auxiliary enclosure canbe less than or equal to about 10% of the enclosure volume of a gasenclosure system. In various embodiments of systems and methods of thepresent teachings, an auxiliary enclosure can be less than or equal toabout 20% of the enclosure volume of a gas enclosure system. Should theopening of an auxiliary enclosure to an ambient environment containingreactive gases be indicated for performing, for example, a maintenanceprocedure, isolating an auxiliary enclosure from the working volume of agas enclosure can prevent contamination of the entire volume of a gasenclosure. Further, given the relatively small volume of an auxiliaryenclosure in comparison to the printing system enclosure portion of agas enclosure, the recovery time for an auxiliary enclosure can takesignificantly less time than recovery time for an entire printing systemenclosure.

As depicted in FIG. 1B, gas enclosure assembly 1000 can include frontbase panel assembly 1220, middle base panel assembly 1320, and rear basepanel assembly 1420, which when fully-constructed form a contiguous baseor pan on which OLED printing system 2000 can be mounted. In a similarfashion as described for gas enclosure assembly 100 of FIG. 1A, thevarious frame members and panels comprising front panel assembly 1200,middle panel assembly 1300, and rear panel assembly 1400 of gasenclosure assembly 1000 can be joined around OLED printing system 2000to form a printing system enclosure. Front panel assembly 1200 can becontoured around printing system 2000 mounted to form a first tunnelenclosure section of a gas enclosure. Similarly, rear panel assembly1400 can be contoured around printing system 2000 to form a secondtunnel enclosure section of a gas enclosure. Additionally, middle panelassembly 1300 can be contoured around a printing system 2000 to form abridge enclosure section of a gas enclosure. A fully constructed gasenclosure assembly, such as gas enclosure assembly 1000, when integratedwith various environmental control systems can form various embodimentsof a gas enclosure system including various embodiments of an OLEDprinting system, such as OLED printing system 2000. According to variousembodiments of a gas enclosure system of the present teachings,environmental control of an interior volume defined by a gas enclosureassembly can include control of lighting, for example, by the number andplacement of lights of a specific wavelength, control of particulatematter using various embodiments of a particle control system, controlof reactive gas species using various embodiments of a gas purificationsystem, and temperature control of a gas enclosure assembly usingvarious embodiments of a thermal regulation system.

An OLED inkjet printing system, such as OLED printing system 2000 ofFIG. 1B, shown in expanded view in FIG. 1C, can be comprised of severaldevices and apparatuses, which allow the reliable placement of ink dropsonto specific locations on a substrate. These devices and apparatusescan include, but are not limited to, a printhead assembly, ink deliverysystem, a motion system for providing relative motion between aprinthead assembly and a substrate, substrate support apparatus,substrate loading and unloading system, and printhead management system.

A printhead assembly can include at least one inkjet head, with at leastone orifice capable of ejecting droplets of ink at a controlled rate,velocity, and size. The inkjet head is fed by an ink supply system whichprovides ink to the inkjet head. As shown in an expanded view of FIG.1C, OLED inkjet printing system 2000 can have a substrate, such assubstrate 2050, which can be supported by a substrate support apparatus,such as a chuck, for example, but not limited by, a vacuum chuck, asubstrate floatation chuck having pressure ports, and a substratefloatation chuck having vacuum and pressure ports. In variousembodiments of systems and methods of the present teachings, a substratesupport apparatus can be a substrate floatation table. As will bediscussed in more detail subsequently herein, substrate floatation table2200 of FIG. 1C can be used for supporting substrate 2050, and inconjunction with a Y-axis motion system, can be part of a substrateconveyance system providing for the frictionless conveyance of substrate2050. A Y-axis motion system of the present teachings can include firstY-axis track 2351 and second Y-axis track 2352, which can include agripper system (not shown) for holding a substrate. Y-axis motion can beprovided by either a linear air bearing or linear mechanical system.Substrate floatation table 2200 of OLED inkjet printing system 2000shown in FIG. 1B and FIG. 1C can define the travel of substrate 2050through gas enclosure assembly 1000 of FIG. 1A during a printingprocess.

FIG. 1C illustrates generally an example of substrate floatation table2200 for a printing system 2000 that can include a floating conveyanceof a substrate, which can have a porous medium to provide floatation. Inthe example of FIG. 1C, a handler or other conveyance can be used toposition a substrate 2050 in first region 2201 of a substrate floatationtable 2200, such as located on a conveyor. The conveyer can position thesubstrate 2050 at a specified location within the printing system suchas using either mechanical contact (e.g., using an array of pins, atray, or a support frame configuration), or using gas cushion tocontrollably float the substrate 2050 (e.g., an “air bearing” tableconfiguration). A printing region 2202 of the substrate floatation table2200 can be used to controllably deposit one or more layers on thesubstrate 2050 during fabrication. The printing region 2202 can also becoupled to an second region 2203 of the substrate floatation table 2200.The conveyer can extend along the first region 2201, the printing region2202, and the second region 2203 of the substrate floatation table 2200,and the substrate 2050 can be repositioned as desired for variousdeposition tasks, or during a single deposition operation. Thecontrolled environments nearby the first region 2201, the printingregion 2202, and the second region 2203 can be commonly-shared.According to various embodiments of printing system 2000 of FIG. 1C,first region 2201 can be an input region, and second region 2203 can bean output region. For various embodiments of printing system 2000 ofFIG. 1C, first region 2201 can be both an input and an output region.Further, function referred to in association with regions 2201, 2202,and 2203, such as input, printing, and output for illustration only.Such regions can be used for other processing steps, such as conveyanceof a substrate, or support of a substrate such as during one or more ofholding, drying, or thermal treatment of the substrate in one or moreother modules.

The printing system 2000 of FIG. 1C can include one or more printheaddevices 2505, each printhead device having one or more printheads; e.g.nozzle printing, thermal jet or ink-jet type. The one or more printheaddevices 2505 can be coupled to or otherwise traversing an overheadcarriage, such as first X-axis carriage assembly 2301. For variousembodiments of printing system 2000 of the present teachings, one ormore printheads of one or more printhead devices 2505 can be configuredto deposit one or more patterned organic layers on the substrate 2050 ina “face up” configuration of the substrate 2050. Such layers can includeone or more of an electron injection or transport layer, a holeinjection or transport layer, a blocking layer, or an emission layer,for example. Such materials can provide one or more electricallyfunctional layers.

According to the floatation schemes shown in FIG. 1C, in an examplewhere the substrate 2050 is supported exclusively by the gas cushion, acombination of positive gas pressure and vacuum can be applied throughthe arrangement of ports or using a distributed porous medium. Such azone having both pressure and vacuum control can effectively provide afluidic spring between the conveyor and a substrate. A combination ofpositive pressure and vacuum control can provide a fluidic spring withbidirectional stiffness. The gap that exists between the substrate(e.g., substrate 2050) and a surface can be referred to as the “flyheight,” and such a height can be controlled or otherwise established bycontrolling the positive pressure and vacuum port states. In thismanner, the substrate Z-axis height can be carefully controlled in, forexample, the printing region 2202. In some embodiments, mechanicalretaining techniques, such as pins or a frame, can be used to restrictlateral translation of the substrate while the substrate is supported bythe gas cushion. Such retaining techniques can include using springloaded structures, such as to reduce the instantaneous forces incidentthe sides of the substrate while the substrate is being retained; thiscan be beneficial as a high force impact between a laterally translatingsubstrate and a retaining means can cause substrate chipping or evencatastrophic breakage.

Elsewhere, as illustrated generally in FIG. 1C, such as where the flyheight need not be controlled precisely, pressure-only floatation zonescan be provided, such as along the conveyor in the first or secondregions 2201 or 2203, or elsewhere. A “transition” floatation zone canbe provided such as where a ratio of pressure to vacuum nozzlesincreases or decreases gradually. In an illustrative example, there canbe an essentially uniform height between a pressure-vacuum zone, atransition zone, and a pressure only zone, so that within tolerances,the three zones can lie essentially in one plane. A fly height of asubstrate over pressure-only zones elsewhere can be greater than the flyheight of a substrate over a pressure-vacuum zone, such as in order toallow enough height so that a substrate will not collide with afloatation table in the pressure-only zones. In an illustrative example,an OLED panel substrate can have a fly height of between about 150micrometers (μ) to about 300μ above pressure-only zones, and thenbetween about 30μ to about 50μ above a pressure-vacuum zone. In anillustrative example, one or more portions of the substrate floatationtable 2200 or other fabrication apparatus can include an “air bearing”assembly provided by NewWay® Air Bearings (Aston, Pa., United States ofAmerica).

A porous medium can be used to establish a distributed pressurized gascushion for floating conveyance or support of the substrate 2050 duringone or more of printing, buffering, drying, or thermal treatment. Forexample, a porous medium “plate” such as coupled to or included as aportion of a conveyor can provide a “distributed” pressure to supportthe substrate 2050 in a manner similar to the use of individual gasports. The use of a distributed pressurized gas cushion without usinglarge gas port apertures can in some instances further improveuniformity and reduce or minimize the formation of mura or other visibledefects, such as in those instances where the use of relatively largegas ports to create a gas cushion leads to non-uniformity, in spite ofthe use of a gas cushion.

A porous medium can be obtained such as from Nano TEM Co., Ltd.(Niigata, Japan), such as having physical dimensions specified to occupyan entirety of the substrate 2050, or specified regions of the substratesuch as display regions or regions outside display regions. Such aporous medium can include a pore size specified to provide a desiredpressurized gas flow over a specified area, while reducing oreliminating mura or other visible defect formation.

Printing requires relative motion between the printhead assembly and thesubstrate. This is accomplished with a motion system, typically a gantryor split axis XYZ system. Either the printhead assembly can move over astationary substrate (gantry style), or both the printhead and substratecan move, in the case of a split axis configuration. In anotherembodiment, a printhead assembly can be substantially stationary; forexample, in the X and Y axes, and the substrate can move in the X and Yaxes relative to the printheads, with Z axis motion provided either by asubstrate support apparatus or by a Z-axis motion system associated witha printhead assembly. As the printheads move relative to the substrate,droplets of ink are ejected at the correct time to be deposited in thedesired location on a substrate. A substrate can be inserted and removedfrom the printer using a substrate loading and unloading system.Depending on the printer configuration, this can be accomplished with amechanical conveyor, a substrate floatation table with a conveyanceassembly, or a substrate transfer robot with end effector. A printheadmanagement system can be comprised of several subsystems which allow forsuch measurement tasks, such as the checking for nozzle firing, as wellas the measurement of drop volume, velocity and trajectory from everynozzle in a printhead, and maintenance tasks, such as wiping or blottingthe inkjet nozzle surface of excess ink, priming and purging a printheadby ejecting ink from an ink supply through the printhead and into awaste basin, and replacement of printheads. Given the variety ofcomponents that can comprise an OLED printing system, variousembodiments of OLED printing system can have a variety of footprints andform factors.

With respect to FIG. 1C, printing system base 2100, can include firstriser 2120 and second riser 2122, upon which bridge 2130 is mounted. Forvarious embodiments of OLED printing system 2000, bridge 2130 cansupport first X-axis carriage assembly 2301 and second X-axis carriageassembly 2302, which can control the movement of first printheadassembly 2501 and second printhead assembly 2502, respectively acrossbridge 2130. For various embodiments of printing system 2000, firstX-axis carriage assembly 2301 and second X-axis carriage assembly 2302can utilize a linear air bearing motion system, which are intrinsicallylow-particle generating. According to various embodiments of a printingsystem of the present teachings, an X-axis carriage can have a Z-axismoving plate mounted thereupon. In FIG. 1C, first X-axis carriageassembly 2301 is depicted with first Z-axis moving plate 2310, whilesecond X-axis carriage assembly 2302 is depicted with second Z-axismoving plate 2312. Though FIG. 1C depicts two carriage assemblies andtwo printhead assemblies, for various embodiments of OLED inkjetprinting system 2000, there can be a single carriage assembly and asingle printhead assembly. For example, either of first printheadassembly 2501 and second printhead assembly 2502 can be mounted on anX,Z-axis carriage assembly, while a camera system for inspectingfeatures of substrate 2050 can be mounted on a second X,Z-axis carriageassembly. Various embodiments of OLED inkjet printing system 2000 canhave a single printhead assembly, for example, either of first printheadassembly 2501 and second printhead assembly 2502 can be mounted on anX,Z-axis carriage assembly, while a UV lamp for curing an encapsulationlayer printed on substrate 2050 can be mounted on a second X,Z-axiscarriage assembly. For various embodiments of OLED inkjet printingsystem 2000, there can be a single printhead assembly, for example,either of first printhead assembly 2501 and second printhead assembly2502, mounted on an X,Z-axis carriage assembly, while a heat source forcuring an encapsulation layer printed on substrate 2050 can be mountedon a second carriage assembly.

In FIG. 1C, each printhead assembly, such as first printhead assembly2501 and second printhead assembly 2502 of FIG. 1C, can have a pluralityof printheads mounted in at least one printhead device, as depicted inpartial view for first printhead assembly 2501, which depicts aplurality of printhead devices 2505. A printhead device can include, forexample, but not limited by, fluidic and electronic connections to atleast one printhead; each printhead having a plurality of nozzles ororifices capable of ejecting ink at a controlled rate, velocity andsize. For various embodiments of printing system 2000, a printheadassembly can include between about 1 to about 60 printhead devices,where each printhead device can have between about 1 to about 30printheads in each printhead device. A printhead, for example, anindustrial inkjet head, can have between about 16 to about 2048 nozzles,which can expel a droplet volume of between about 0.1 pL to about 200pL.

According to various embodiments of a gas enclosure system of thepresent teachings, given the sheer number of printhead devices andprintheads, first printhead management system 2701 and second printheadmanagement system 2702 can be housed in an auxiliary enclosure, whichcan be isolated from a printing system enclosure during a printingprocess for performing various measurement and maintenance tasks withlittle or no interruption to the printing process. As can be seen inFIG. 1C, first printhead assembly 2501 can be seen positioned relativeto first printhead management system 2701 for ready performance ofvarious measurement and maintenance procedures that can be performed byfirst printhead management system apparatuses 2707, 2709 and 2711.Apparatuses 2707, 2709, and 2011 can be any of a variety of subsystemsor modules for performing various printhead management functions. Forexample apparatuses 2707, 2709, and 2011 can be any of a dropmeasurement module, a printhead replacement module, a purge basinmodule, and a blotter module. As depicted in FIG. 1C, first printheadmanagement system apparatuses 2707, 2709 and 2711 and can be mounted onlinear rail motion system 2705 for positioning relative to firstprinthead assembly 2501. Similarly, second printhead management system2702, which can have a similar complement of apparatuses, can haveprinthead management apparatuses mounted on linear rail motion system2706 for positioning relative to first printhead assembly 2502.

With respect to various embodiments of a gas enclosure assembly havingan auxiliary enclosure that can be closed off from, as well as sealablyisolated from a first working volume, for example, a printing systemenclosure, reference is made again to FIG. 1B. As depicted in FIG. 1C,there can be four isolators on OLED printing system 2000; first isolatorset 2110 (second not shown on opposing side) and second isolator set2112 (second not shown on opposing side), which support substratefloatation table 2200 of OLED printing system 2000. For gas enclosureassembly 1000 of FIG. 1B, first isolator set 2110 and second isolatorset 2112 can be mounted in each of a respective isolator well panel,such as first isolator wall panel 1325 and second isolator wall panel1327 of middle base panel assembly 1320. For gas enclosure assembly 1000of FIG. 1B, middle base assembly 1320 can include first auxiliaryenclosure 1330, as well as second auxiliary enclosure 1370. FIG. 1B ofgas enclosure assembly 1000 depicts first auxiliary enclosure 1330 thatcan include first back wall panel assembly 1338. Similarly, alsodepicted is second auxiliary enclosure 1370 that can include second backwall panel assembly 1378. First back wall panel assembly 1338 of firstauxiliary enclosure 1330 can be constructed in a similar fashion asshown for second back wall panel assembly 1378. Second back wall panelassembly 1378 of second auxiliary enclosure 1370 can be constructed fromsecond back wall frame assembly 1378 having second seal-support panel1375 sealably mounted to second back wall frame assembly 1378. Secondseal-support panel 1375 can have second passage 1365, which is proximalto a second end of base 2100 (not shown). Second seal 1367 can bemounted on second seal-support panel 1375 around second passage 1365. Afirst seal can be similarly positioned and mounted around a firstpassage for first auxiliary enclosure 1330. Each passage in auxiliarypanel assembly 1330 and auxiliary panel assembly 1370 can accommodatehaving each maintenance system platform, such as first and secondmaintenance system platforms 2703 and 2704 of FIG. 1C pass through thepassages. As will be discussed in more detail subsequently herein, inorder to sealably isolate auxiliary panel assembly 1330 and auxiliarypanel assembly 1370 the passages, such as second passage 1365 of FIG. 1Bmust be sealable. It is contemplated that various seals, such as aninflatable seal, a bellows seal and a lip seal can be used for sealing apassage, such as second passage 1365 of FIG. 1B, around a maintenanceplatform affixed to a printing system base.

First auxiliary enclosure 1330 and second auxiliary enclosure 1370 caninclude first printhead assembly opening 1342 of first floor panelassembly 1341 and second printhead assembly opening 1382 of second floorpanel assembly 1381; respectively. First floor panel assembly 1341 isdepicted in FIG. 1B as part of first middle enclosure panel assembly1340 of middle panel assembly 1300. First floor panel assembly 1341 is apanel assembly in common with both first middle enclosure panel assembly1340 and first auxiliary enclosure 1330. Second floor panel assembly1381 is depicted in FIG. 1B as part of second middle enclosure panelassembly 1380 of middle panel assembly 1300. Second floor panel assembly1381 is a panel assembly in common with both second middle enclosurepanel assembly 1380 and second auxiliary enclosure 1370.

As previously discussed herein, first printhead assembly 2501 can behoused in first printhead assembly enclosure 2503, and second printheadassembly 2502 can be housed in second printhead assembly enclosure 2504.According to systems and methods of the present teachings, firstprinthead assembly enclosure 2503 and second printhead assemblyenclosure 2504 can have an opening at the bottom that can have a rim(not shown), so that various printhead assemblies can be positioned forprinting during a printing process. Additionally, the portions of firstprinthead assembly enclosure 2503 and second printhead assemblyenclosure 2504 forming a housing can be constructed as previouslydescribed for various panel assemblies, so that the frame assemblymembers and panels are capable of providing an hermetically-sealedenclosure.

A compressible gasket which can additionally be used for the hermeticsealing of various frame members, can be affixed around each of firstprinthead assembly opening 1342 and second printhead assembly opening1382, or alternatively around the rim of first printhead assemblyenclosure 2503 and second printhead assembly enclosure 2504.

According to the present teachings, compressible gasket material can beselected from, for example, but not limited by, any in the class ofclosed-cell polymeric materials, also referred to in the art as expandedrubber materials or expanded polymer materials. Briefly, a closed-cellpolymer is prepared in a fashion whereby gas is enclosed in discretecells; where each discrete cell is enclosed by the polymeric material.Properties of compressible closed-cell polymeric gasket materials thatare desirable for use in gas-tight sealing of frame and panel componentsinclude, but are not limited by, that they are robust to chemical attackover a wide range of chemical species, possess excellentmoisture-barrier properties, are resilient over a broad temperaturerange, and they are resistant to a permanent compression set. Ingeneral, compared to open-cell-structured polymeric materials,closed-cell polymeric materials have higher dimensional stability, lowermoisture absorption coefficients, and higher strength. Various types ofpolymeric materials from which closed-cell polymeric materials can bemade include, for example, but not limited by, silicone, neoprene,ethylene-propylene-diene terpolymer (EPT); polymers and composites madeusing ethylene-propylene-diene-monomer (EPDM), vinyl nitrile,styrene-butadiene rubber (SBR), and various copolymers and blendsthereof.

In addition to close-cell compressible gasket materials, another exampleof a class of compressible gasket material having desired attributes foruse in constructing embodiments of a gas enclosure assembly according tothe present teachings includes the class of hollow-extruded compressiblegasket materials. Hollow-extruded gasket materials as a class ofmaterials have the desirable attributes, including, but not limited by,that they are robust to chemical attack over a wide range of chemicalspecies, possess excellent moisture-barrier properties, are resilientover a broad temperature range, and they are resistant to a permanentcompression set. Such hollow-extruded compressible gasket materials cancome in a wide variety of form factors, such as for example, but notlimited by, U-cell, D-cell, square-cell, rectangular-cell, as well asany of a variety of custom form factor hollow-extruded gasket materials.Various hollow-extruded gasket materials can be fabricated frompolymeric materials that are used for closed-cell compressible gasketfabrication. For example, but not limited by, various embodiments ofhollow-extruded gaskets can be fabricated from silicone, neoprene,ethylene-propylene-diene terpolymer (EPT); polymers and composites madeusing ethylene-propylene-diene-monomer (EPDM), vinyl nitrile,styrene-butadiene rubber (SBR), and various copolymers and blendsthereof. Compression of such hollow cell gasket materials should notexceed about 50% deflection in order to maintain the desired attributes.

As depicted in FIG. 1B, first printhead assembly docking gasket 1345 andsecond printhead assembly docking gasket 1385 can be affixed aroundfirst printhead assembly opening 1342 and second printhead assemblyopening 1382, respectively. During various printhead measurement andmaintenance procedures, first printhead assembly 2501 and secondprinthead assembly 2502 can be positioned by first X,Z-axis carriageassembly 2301 and second X,Z-axis carriage assembly 2302, respectively,over first printhead assembly opening 1342 of first floor panel assembly1341 and second printhead assembly opening 1382 of second floor panelassembly 1381, respectively. In that regard, for various printheadmeasurement and maintenance procedures, first printhead assembly 2501and second printhead assembly 2502 can be positioned over firstprinthead assembly opening 1342 of first floor panel assembly 1341 andsecond printhead assembly opening 1382 of second floor panel assembly1381, respectively, without covering or sealing first printhead assemblyopening 1342 and second printhead assembly opening 1382. First X,Z-axiscarriage assembly 2301 and second X,Z-axis carriage assembly 2302 candock first printhead assembly enclosure 2503 and second printheadassembly enclosure 2504, respectively, with first auxiliary enclosure1330 and second auxiliary enclosure 1370, respectively. In variousprinthead measurement and maintenance procedures, such docking mayeffectively close first printhead assembly opening 1342 and secondprinthead assembly opening 1382 without the need for sealing firstprinthead assembly opening 1342 and second printhead assembly opening1382. For various printhead measurement and maintenance procedures, thedocking can include the formation of a gasket seal between each of theprinthead assembly enclosures and the printhead management system panelassemblies. In conjunction with sealably closing passages, such assecond passage 1365 and a complementary first passage of FIG. 1B, whenfirst printhead assembly enclosure 2503 and second printhead assemblyenclosure 2504 are docked with first auxiliary enclosure 1330 and secondauxiliary enclosure 1370 to sealably close first printhead assemblyopening 1342 and second printhead assembly opening 1382, the combinedstructures so formed are hermetically sealed.

Additionally, according to the present teachings, an auxiliary enclosurecan be isolated from, for example, another interior enclosure volume,such as the printing system enclosure, as well as the exterior of a gasenclosure assembly, by using a structural closure to sealably close apassageway, such as first printhead assembly opening 1342 and secondprinthead assembly opening 1382 of FIG. 1B. According to the presentteachings, a structural closure can include a variety of sealablecoverings for an opening or passageway; such opening or passagewayincluding non-limiting examples of an enclosure panel opening orpassageway. According to systems and methods of the present teachings, agate can be any structural closure that can be used to reversibly coveror reversibly sealably close any opening or passageway using pneumatic,hydraulic, electrical, or manual actuation. As such, first printheadassembly opening 1342 and second printhead assembly opening 1382 of FIG.1B can be reversibly covered or reversibly sealably closed using a gate.

In the expanded view of OLED printing system 2000 of FIG. 1C, variousembodiments of a printing system can include substrate floatation table2200, supported by substrate floatation table base 2220. Substratefloatation table base 2220 can be mounted on printing system base 2100.Substrate floatation table 2200 of OLED printing system can supportsubstrate 2050, as well as defining the travel over which substrate 2050can be moved through gas enclosure assembly 1000 during the printing ofan OLED substrate. A Y-axis motion system of the present teachings caninclude first Y-axis track 2351 and second Y-axis track 2352, which caninclude a gripper system (not shown) for holding a substrate. Y-axismotion can be provided by either a linear air bearing or linearmechanical system. In that regard, in conjunction with a motion system;as depicted in FIG. 1C, a Y-axis motion system, substrate floatationtable 2200 can provide frictionless conveyance of substrate 2050 througha printing system.

In reference to FIG. 2, printing system 2001 can have all of theelements previously described for printing system 2000 of FIG. 1C. Forexample, but not limited by, printing system 2001 of FIG. 2 can haveservice bundle housing exhaust system 2400 for containing and exhaustingparticles generated from a service bundle. Service bundle housingexhaust system 2400 of printing system 2001 can include service bundlehousing 2410, which can house a service bundle. According to the presentteachings, a service bundle can be operatively connected to a printingsystem to provide various optical, electrical, mechanical and fluidicconnections required to operate various devices and apparatuses in a gasenclosure system, for example, but not limited by, various devices andapparatuses associated with a printing system. A positive flowdifferential through service bundle housing exhaust system 2400 canensure that particles generated by a service bundle in service bundlehousing 2410 can be directed into service bundle housing exhaust plenum2420 and then into a gas circulation and filtration system throughservice bundle housing exhaust plenum first duct 2422 and service bundlehousing exhaust plenum second duct 2424. Printing system 2001 of FIG. 2can have substrate support apparatus 2250 for supporting substrate 2050,which can be positioned with precision in the Y-axis direction usingY-axis positioning system 2355. Both substrate support apparatus 2250and Y-axis positioning system 2355 are supported by printing system base2101. Substrate support apparatus 2250 can be mounted on Y-axis motionassembly 2355 and can be moved on rail system 2360 using, for example,but not limited by, a linear bearing system; either utilizing mechanicalbearings or air bearings. For various embodiments of gas enclosuresystems, an air bearing motion system helps facilitation frictionlessconveyance in the Y-axis direction for a substrate placed on substratesupport apparatus 2250. Y-axis motion system 2355 can also optionallyuse dual rail motion, once again, provided by a linear air bearingmotion system or a linear mechanical bearing motion system.

Regarding motion systems supporting various carriage assemblies,printing system 2001 of FIG. 2 can have first X-axis carriage assembly2300A that is depicted having printhead assembly 2500 mounted thereuponand second X-axis carriage assembly 2300B that is depicted having cameraassembly 2550 mounted thereupon. Substrate 2050, which is on substratesupport apparatus 2250, can be located in various positions proximal tobridge 2130, for example, during a printing process. Substrate supportapparatus 2250 can be mounted on printing system base 2101. In FIG. 2,printing system 2001 can have first X-axis carriage assembly 2300A andsecond X-axis carriage assembly 2300B mounted on bridge 2130. FirstX-axis carriage assembly 2300A can also include first Z-axis movingplate 2310A for the Z-axis positioning of printhead assembly 2500, whilesecond X-axis carriage assembly 2300B can have second Z-axis movingplate 2310B for the Z-axis positioning of camera assembly 2550. In thatregard, various embodiments of carriage assemblies 2300A and 2300B canprovide precision X,Z positioning with respect to a substrate positionedon substrate support 2250 for printhead assembly 2500 and cameraassembly 2550, respectively. For various embodiments of printing system2004, first X-axis carriage assembly 2300A and second X-axis carriageassembly 2300B can utilize a linear air bearing motion system, which isintrinsically low-particle generating.

Camera assembly 2550 of FIG. 2 can be a high-speed, high-resolutioncamera. A camera assembly 2550 can include camera 2552, camera mountassembly 2554 and lens assembly 2556. Camera assembly 2550 can bemounted to motion system 2300B on Z-axis moving plate 2310B, via cameramount assembly 2556. Camera 2552 can be any image sensor device thatconverts an optical image into an electronic signal, such as by way ofnon-limiting example, a charge-coupled device (CCD), a complementarymetal-oxide-semiconductor (CMOS) device or N-typemetal-oxide-semiconductor (NMOS) device. Various image sensor devicescan be configured as an array of sensors for an area scan camera, or asingle row of sensors, for a line scan camera. Camera assembly 2550 canbe connected to image processing system that can include, for example, acomputer for storing, processing, and providing results. As previouslydiscussed herein for printing system 2001 of FIG. 2, Z-axis moving plate2310B can controllably adjust the Z-axis position of camera assembly2550 relative to substrate 2050. During various processes, such as forexample, printing and data collection, substrate 2050 can becontrollably positioned relative to the camera assembly 2550 using theX-axis motion system 2300B and Y-axis motion system 2355.

Accordingly, the split axis motion system of FIG. 2 can provide precisepositioning of the camera assembly 2550 and substrate 2050 relative toone another in three dimensions in order to capture image data on anypart of the substrate 2050 at any desired focus and/or height. Moreover,precision XYZ motion of a camera relative to a substrate can be done foreither area scanning or line scanning processes. As previously discussedherein, other motion systems, such as a gantry motion system, can alsobe used to provide precision movement in three dimensions between, forexample, a printhead assembly and/or a camera assembly, relative to asubstrate. Additionally, lighting can be mounted in various positions;either on an X-axis motion system or on a substrate support apparatusproximal to a substrate, and combinations thereof. In that regard,lighting can be positioned according to performing various lightfieldand darkfield analyses, and combinations thereof. Various embodiments ofa motion system can position camera assembly 2550 relative to substrate2050 using a continuous or a stepped motion or a combination thereof tocapture a series of one or more images of the surface of substrate 2050.Each image can encompass an area associated with one or more pixelwells, associated electronic circuitry components, pathways andconnectors of an OLED substrate. By using image processing, images ofparticles can be obtained, and size and number of particles of aspecific size determined. In various embodiments of systems and methodsof the present teachings, a line scan camera having about 8192 pixels,with a working height of about 190 mm, and capable of scanning at about34 kHz can be used. Additionally, more than one camera can be mounted onan X-axis carriage assembly for various embodiments of a printing systemcamera assembly, where each camera can have different specificationsregarding field of view and resolution. For example, one camera can be aline scan camera for in situ particle inspection, while a second cameracan be for regular navigation of a substrate in a gas enclosure system.Such a camera useful for regular navigation can be an area scan camerahaving a field of view in the range of about 5.4 mm×4 mm with amagnification of about 0.9× to about 10.6 mm×8 mm with a magnificationof about 0.45×. In still other embodiments, one camera can be a linescan camera for in situ particle inspection, while a second camera canbe for precise navigation of a substrate in a gas enclosure system, forexample, for substrate alignment. Such a camera can be useful forprecise navigation can be an area scan camera having a field of view ofabout 0.7 mm×0.5 mm with a magnification of about 7.2×.

With respect to in situ inspection of an OLED substrate, variousembodiments of a printing system camera assembly, such as cameraassembly 2550 of printing system 2001 depicted in FIG. 2, can be used toinspect a panel without significant impact to total average cycle time(TACT). For example, a Gen 8.5 substrate can be scanned for on-substrateparticulate matter in less than 70 seconds. In addition to in situinspection of OLED substrate, a printing system camera assembly can beused for a system validation study by using a test substrate todetermine whether or not a sufficiently low particle environment for agas enclosure system can be verified prior to using the gas enclosuresystem for a printing process.

Various embodiments of a gas enclosure system can have a gas circulationand filtration system in which gas can be circulated and filtered invarious zones. In various embodiments of gas enclosure systems andmethods of the present teachings, a gas circulation and filtrationsystem can have a tunnel baffle plate that directs the circulation offiltered gas through an opening that creates a transition-flow zonethrough which gas can flow into a bridge circulation and filtrationzone. A tunnel circulation and filtration system can provide for thecross-flow of gas across a substrate support apparatus. In variousembodiments of systems and methods of the present teachings, thecross-flow of gas across a substrate support apparatus in a tunnelcirculation and filtration zone can be substantially laminar. A gasenclosure system having a tunnel circulation and filtration zone canhave a transition-flow zone proximal to a carriage assembly that drawsgas away from a substrate located below the carriage assembly. The gasdrawn into the transition flow zone can be drawn through an opening in atunnel baffle plate. Various embodiments of a gas enclosure system canhave a bridge circulation and filtration system that can providecirculation and filtration of gas about a printing system bridge andrelated apparatuses and devices, and is in flow communication with thetransition-flow zone. Various embodiments of a gas circulation andfiltration system of the present teachings can effectively remove bothairborne particulate matter, as well as particulate matter generatedproximal to a substrate during a printing process.

FIG. 3A and FIG. 3B are schematic front cross-section views of gasenclosure system 500A, which depicts a cross section of a first tunnelenclosure section 1200 that illustrate generally tunnel circulation andfiltration system 1500. Additionally, for perspective and context,features as described for various embodiments of gas enclosure 1000 ofFIG. 1A, as well as printing system 2000 of FIG. 1B and FIG. 1C aredepicted in phantom view through a section of bridge enclosure section1300. Printing system 2002, which can be housed in gas enclosure 1002,can have printing system base 2100, which can be supported by at leasttwo sets of isolators such as isolator set 2110 that includes isolators2110A and 2110B of FIG. 3A and FIG. 3B. A Y-axis motion system can bemounted on printing system base 2100 and can include Y-axis track 2350,supported by Y-axis track support 2355. Substrate 2050 can be floatinglysupported by substrate floatation table 2200. Printing system base 2100can support first riser 2120 and second riser 2122, upon which bridge2130 can be mounted. Printing system bridge 2130 can support firstX-axis carriage assembly 2301, upon which printhead assembly 2500 can bemounted, and second X-axis carriage assembly 2302, upon which cameraassembly 2550 can be mounted.

Additionally, gas enclosure system 500A can have auxiliary enclosure1330, depicted in phantom view, which can enclose printhead managementsystem 2701. Printing system 2000 of FIG. 1B depicts a gas enclosurehaving first auxiliary enclosure 1330 and second auxiliary enclosure1370, while in FIG. 3A and FIG. 3B, auxiliary enclosure 1330 isindicated. As such, various embodiments of systems and methods of thepresent teachings can have a gas enclosure with one auxiliary enclosure.In various embodiments of systems and methods of the present teachings,a gas enclosure can have two auxiliary enclosures. Auxiliary enclosure1330 can be in flow communication with the printing system enclosure ofgas enclosure system 500A through printhead assembly opening 1342, andcan be sealably isolated from the remaining volume of gas enclosure1002, by way of non-limiting example, by docking first printheadassembly 2500 onto first printhead assembly docking gasket 1345. As willbe discussed subsequently in more detail herein, for various embodimentsof a multi-zone gas circulation and filtration system of the presentteachings, tunnel baffle plate 2150, shown partially in phantom view inFIG. 3A and FIG. 3B, can be mounted horizontally in a bridge enclosuresection of a gas enclosure.

As depicted in the schematic front cross-section view of FIG. 3A andFIG. 3B, various embodiments of tunnel circulation and filtration system1500 can include inlet baffle 2140, which can include inlet bafflesupport 2142. Inlet baffle 2140, in conjunction with tunnel enclosure1200, can direct the flow of gas across floatation table 2200. Tunnelcirculation and filtration system 1500 can include gas intake housing1510, in which fan 1520, heat exchanger 1530, and filter unit 1540 canbe mounted in series. Filter unit 1540 can have tunnel circulation andfiltration diffuser 1545 in series with filter unit 1540, as depicted inFIG. 3A and FIG. 3B. In various embodiments, tunnel circulation andfiltration diffuser 1545 can be a perforated metallic plate for creatinga controlled distribution of flow. Various embodiments of tunnelcirculation and filtration diffuser 1545 can be a filtration materialhaving, for example, but not limited by, a porous structure for creatinga controlled distribution of flow. For various embodiments of tunnelcirculation and filtration diffuser 1545, gas flowing through thediffuser can provide for a desired controlled pressure drop, which canresult in a controlled flow on an exit side of a diffuser. For example,a diffuser can be designed to offset an uneven flow profile entering aflow-directing structure, such as a duct, a baffle or a plenum, leadingto uniform flow on an exit side of a diffuser. Additionally, variousembodiments of a diffuser according to the present teachings can bedesigned for a specifically controlled non-uniform flow profile on anexit side of a diffuser.

For various embodiments of tunnel circulation and filtration system1500, fan 1520 and filter unit 1540 can be combined into a fan filterunit. Various embodiments of a tunnel circulation and filtration zonecan include outlet baffle 2141, which can include outlet baffle support2143. Outlet baffle 2141, in conjunction with tunnel enclosure 1200, candirect the flow of gas in a downward direction to be circulated acrossfloatation table 2200 and around a portion of a printing system housedin a first tunnel enclosure and second tunnel enclosure section (seealso FIG. 1B), thereby providing a cross-flow path in a first tunnelenclosure and second tunnel enclosure section. In that regard, variousembodiments of systems and methods of the present teachings can have afirst tunnel circulation and filtration zone, as well as a second tunnelcirculation and filtration zone. Various embodiments of tunnelcirculation and filtration system 1500 can provide filtered gas thatcirculates across the tunnel zone of a gas enclosure system. As depictedin the cross-section view of FIG. 3A and FIG. 3B, various embodiments ofa tunnel circulation and filtration system 1500 direct inert gas acrosssubstrate 2050. For gas enclosure system 500A, inlet baffle 2140 andoutlet baffle 2141, in conjunction with first tunnel enclosure section1200 can be used to direct the flow of filtered gas laterally, so thatgas is circulated in a cross-flow path through gas enclosure system500A.

In various embodiments of systems and methods of the present teachings,tunnel circulation and filtration system 1500 of FIG. 3A and FIG. 3B canprovide circulation and filtration for both the first tunnel enclosuresection, as well as the second tunnel enclosure section. According tovarious embodiments of systems and methods of the present teachings, asecond tunnel circulation and filtration system having the componentsdescribed for tunnel circulation and filtration system 1500 of firsttunnel enclosure section 1200 of FIG. 3A and FIG. 3B can be provided fora second tunnel enclosure section, such as second tunnel enclosuresection 1400 of FIG. 1A.

As will be discussed in more detail subsequently herein, gas enclosuresystem 500A can be in flow communication with a gas enclosurepurification system. As depicted in FIG. 3A, gas purification firstoutlet line 3131A can provide flow communication between gas enclosuresystem 500A and a gas purification system. Similarly, gas purificationinlet line 3133 can be a return line bringing purified inert gas to gasenclosure system 500A from a gas purification system. For example,during a printing process, gas flowing into auxiliary enclosure 1330through first printhead assembly opening 1342 of FIG. 3A can be cycledto a gas purification system from gas purification first outlet line3131A and purified inert gas can be directed back into gas enclosure1002 through gas purification inlet line 3133. During such a process,gas purification second outlet line 3131B can be isolated from flowcommunication with a purification system, for example, by use of a valve(not shown) in a closed position. As shown in FIG. 3B, first printheadassembly opening 1342 can be constructed as a sealable section of gasenclosure assembly, for example, by the positioning of first printheadassembly 2500 onto first printhead assembly docking gasket 1345.According to systems and methods of the present teachings, an auxiliaryenclosure can be sealable isolated from a printing system enclosure, andcan be opened to an environment external a gas enclosure assembly. Forexample, while performing a maintenance procedure, auxiliary enclosure1300 can be opened to the environment, as depicted in FIG. 3B, withoutexposing the remaining volume of gas enclosure 1002 to the externalenvironment. As depicted in FIG. 3B, during such a process, gaspurification second outlet line 3131B would be in flow communicationwith a purification system, and purified inert gas can be directed backinto gas enclosure 1002 through gas purification inlet line 3133. Duringsuch a procedure, gas purification first outlet line 3131A can beisolated from flow communication with a purification system, forexample, by use of a valve (not shown) in a closed position.

As indicated in FIG. 3B, FIG. 4 is an enlarged view of a section ofprinting system 2002, which depicts filter unit 1540 of first tunnelcirculation and filtration system 1500 X under bridge 2130 proximal tosubstrate 2050. Substrate 2050 is depicted in FIG. 4 as floatinglysupported by floatation table 2200. First X-axis carriage assembly 2301,which has at least one printhead assembly, is controllably positioned inX-axis movement relative to substrate 2050 using a precision movementsystem. Various components essential to the printing system operation,for example, a service bundle are located proximal to substrate 2050positioned for printing and can be an ongoing source of particulatematter. As shown in FIG. 4, inlet baffle 2140 in combination with firsttunnel enclosure section 1200, can be used to direct a filtered gasstream over substrate 2050, indicated as substrate cross flowcirculation path 10. Substrate cross flow circulation path 10 asdepicted in FIG. 4 has cross-sectional dimensions X in the horizontaldirection defined by X₁ and X₂ and Y in the vertical direction definedby Y₁ and Y₂. The flow velocity of a circulation and filtration system,such as circulation and filtration system 1500 (see FIG. 3A), is set inaccordance with the longest horizontal dimension of substrate cross flowcirculation path 10, so that a particle entering the flow stream atabout Y₁ will be swept through substrate cross flow circulation path 10and thereby will not make contact with substrate 2050.

The data in Table 3, shown below, summarizes a limit particle size thatcan be swept through substrate cross flow circulation path 10 of FIG. 4.The calculations were made in consideration of the longest horizontaldimension of each generation substrate size, as well as a range of flowrates from 0.1 to 1 m/s, and additionally in consideration of variationof densities of particles in the range of 1000-9000 kg/m³. The upperlimit of a particle size; reported as diameter in microns [ ], whichincludes the value of a diameter reported in Table 3 (i. e. ≤), wasdetermined in consideration of two cases bounded by: 1) the lowest flowrate of 0.1 m/s and highest particle density of a particle of 9000 kg/m³and 2) the highest flow rate of 1 m/s and lowest density of a particleof 1000 kg/m³. In that regard, the diameters reported represent a valuein between those two bounds. The trend of the data indicate that as thelongest horizontal dimension of substrate increases under the conditionof fairly constant flow velocity, the average limit diameter of aparticle that can be effectively swept through cross flow circulationpath 10 decreases. However, the smallest particle size reported is forthe longest cross flow circulation path for a Gen 10 substrate, and issubstantially larger than particle sizes of interest. Accordingly, thesummary of calculations presented in Table 3 demonstrate theeffectiveness of various embodiments of systems and methods of thepresent teachings that utilize cross flow for preventing particles fromcontaminating a substrate surface during processing.

TABLE 3 Limit of particle size that can be swept by cross flow. LimitParticle Size: Generation ID X (mm) Y (mm) Area (m²) Diameter ≤ μ[microns] Gen 3.0 550 650 0.36 42 Gen 3.5 610 720 0.44 40 Gen 3.5 620750 0.47 40 Gen 4 680 880 0.6 38 Gen 4 730 920 0.67 37 Gen 5 1100 12501.38 30 Gen 5 1100 1300 1.43 30 Gen 5.5 1300 1500 1.95 28 Gen 6 15001850 2.78 26 Gen 7.5 1950 2250 4.39 23 Gen 8 2160 2400 5.18 21 Gen 82160 2460 5.31 21 Gen 8.5 2200 2500 5.5 21 Gen 9 2400 2800 6.72 20 Gen10 2850 3050 8.69 19

Accordingly, the design of various embodiments of first tunnelcirculation and filtration system 1500, in conjunction with otherlow-particle systems and methods of the present teachings, can provide asubstantially low particle environment proximal a substrate for variousembodiments of a gas enclosure system. As previously discussed herein,such a substantially low particle environment can have a specificationfor airborne particulate matter, as well as for on-substrate particulatematter. various embodiments of a multi-zone gas circulation andfiltration system of the present teachings can effectively remove bothairborne particulate matter in various sections of a gas enclosure, aswell as particulate matter generated proximal to a substrate, forexample, during a printing process.

FIG. 5A is a schematic top section view of gas enclosure system 500A,depicting various embodiments of a tunnel circulation and filtrationzone, as well various embodiments of a bridge circulation and filtrationzone. The section is taken through gas enclosure 1002 above opening 1342of auxiliary enclosure 1330 (see FIG. 1B). As previously discussedherein, various embodiments of systems and methods of the presentteachings can have a gas enclosure with one auxiliary enclosure.Additionally, for various embodiments of systems and methods of thepresent teachings, a gas enclosure can have two auxiliary enclosures. Inthe schematic rending of FIG. 5A, tunnel cross flow circulation path 20is depicted for first tunnel enclosure section 1200 and second tunnelenclosure section 1400 of gas enclosure system 500A. Tunnel cross flowcirculation path 20 of FIG. 5A is depicted as a flow path circulatinggas around a printing system, which can include floatation table 2200(see FIG. 1B). According to various embodiments of a multi-zonecirculation and filtration system of the present teachings, first tunnelcirculation and filtration system 1500A can be positioned approximatelymid-way in first tunnel enclosure section 1200. For various embodimentsof systems and methods of the present teachings, gas enclosure system500A may utilize a single tunnel circulation and filtration system. Asdepicted in FIG. 5A, various systems and methods of the presentteachings can utilize two tunnel circulation and filtration systems, andcan include second tunnel circulation and filtration system 1500B, whichcan be positioned approximately mid-way in second tunnel enclosuresection 1400.

For gas enclosure system 500A of FIG. 5A, tunnel baffle plate 2150,mounted in bridge enclosure section 1300, can have first riser opening2152, which accommodates first riser 2120, as well as having secondriser opening 2154 for accommodating second riser 2122. Additionally,tunnel baffle plate 2150 can have carriage assembly opening 2156, whichcan allow for the movement of various carriage assemblies that can bemounted on a printing system bridge, such as X-axis carriage assembly2301 depicted in FIG. 5A. Tunnel baffle plate carriage assembly opening2156 can be in flow communication with various embodiments of a bridgecirculation and filtration zone. Tunnel baffle plate carriage assemblyopening 2156 can allow for transition zone flow path 30, as indicated bythe direction of flow indicators in transition zone flow path 30. Assuch, tunnel baffle plate 2150 provides for flow communication from atunnel circulation and filtration zone to a bridge circulation andfiltration zone.

FIG. 5B is a schematic long section view through gas enclosure system500A. Gas enclosure system 500A can have a printing system that caninclude floatation table 2200 that is supported by a first set ofisolators 2110 and a second set of isolators 2112, as well as mounted onprinting system base 2100. In FIG. 5B, tunnel cross flow circulationpath 20 is depicted in long section view of gas enclosure 1002, withflow direction indicators showing the cross circulation path of filteredgas in the tunnel circulation and filtration zone of gas enclosuresystem 500A. Gas enclosure 1002 can have inlet opening or inlet gate1242 for receiving a substrate, as well as outlet opening or outlet gate1442 for transitioning a substrate from gas enclosure assembly 500A. Invarious embodiments of gas enclosure system 500A, there may be only asingle gate 1242, which can be both an inlet and outlet gate. Variousembodiments of a Y-axis motion system can move a substrate in the Y-axisdirection relative to X-axis carriage assembly 2301 mounted on bridge2130, which can have at least one printhead assembly mounted thereupon,such as printhead assembly 2500 depicted in FIG. 5B.

As depicted in FIG. 5B for gas enclosure system 500A, tunnel baffleplate carriage assembly opening 2156 can allow for transition zone flowpath 30. In that regard, tunnel baffle plate 2150 can provide flowcommunication between a tunnel circulation and filtration zone and abridge circulation and filtration zone. Bridge circulation andfiltration system 1550A can have bridge circulation flow path 40, whichcan draw filtered gas in an upward direction around, for example, X-axiscarriage assembly 2301. Bridge circulation and filtration system 1550Acan include service bundle housing exhaust system 2400, which caninclude service bundle housing 2410, as well as bridge enclosure sectionexhaust duct 2450, which can exhaust service bundle housing 2410, andgenerally the bridge enclosure section, as indicated by flow path 40.Bridge enclosure section exhaust duct 2450 can have bridge enclosuresection exhaust duct diffuser 2455, which can provide for a desiredcontrolled pressure drop that can result in a controlled flow intobridge enclosure section exhaust duct 2450. In various embodiments,bridge enclosure section exhaust duct diffuser 2455 can be a perforatedmetallic plate for creating a controlled distribution of flow. Variousembodiments of bridge enclosure section exhaust duct diffuser 2455 canbe a filtration material having, for example, but not limited by, aporous structure for creating a controlled distribution of flow. Forvarious embodiments of bridge enclosure section exhaust duct diffuser2455, gas flowing through the diffuser can provide for a desiredcontrolled pressure drop, which can result in a controlled flow on anexit side of a diffuser. For example, a diffuser can be designed tooffset an uneven flow profile entering a flow-directing structure, suchas a duct, a baffle or a plenum, leading to uniform flow on an exit sideof a diffuser. Additionally, various embodiments of a diffuser accordingto the present teachings can be designed for a specifically controllednon-uniform flow profile on an exit side of a diffuser.

Bridge circulation and filtration system 1550A can include bridgecirculation and filtration system intake duct 1560, which can be in flowcommunication with bridge enclosure section exhaust duct 2450. Bridgecirculation and filtration system 1550A can include fan 1570, heatexchanger 1580, and filter 1590, which can be mounted within bridgecirculation and filtration system intake duct 1560. For variousembodiments of bridge circulation and filtration system 1550A, fan 1570and filter unit 1590 can be combined into a fan filter unit. Bridgecirculation and filtration system intake duct 1560 can be in flowcommunication with bridge circulation and filtration system return duct1565. Bridge circulation and filtration system return duct 1565 can bein flow communication with a tunnel enclosure section, as indicated inFIG. 5B. Gas enclosure system 500A of FIG. 5B can have more than onebridge circulation and filtration return duct. For various embodimentsof a multi-zone circulation and filtration system, a bridge circulationand filtration system return duct can complete the flow communicationbetween a tunnel circulation and filtration zone and a bridgecirculation and filtration zone.

Various embodiments of a cross flow design for systems and methods ofthe present teachings may utilize a combination of flow-directingstructures, such as baffle plates, ducts and plenums to provide for atunnel circulation and filtration zone and a bridge circulation andfiltration zone that are not in active flow communication via aflow-directing structure. For example, FIG. 6 illustrates generally across section view of an embodiments of the present teachings in which atunnel circulation and filtration zone and a bridge circulation andfiltration zone that are substantially independent zones not in directedflow communication via a flow-directing structure.

Similarly to gas enclosure system 500A of FIG. 3A and FIG. 3B, FIG. 6illustrates generally tunnel circulation and filtration system 1500B ofgas enclosure system 500B. Additionally, for perspective and context,features as described for various embodiments of gas enclosure 1000 ofFIG. 1A, as well as printing system 2000 of FIG. 1B and FIG. 1C aredepicted in phantom view through a section of bridge enclosure section1300. Gas enclosure system 500B can have printing system 2002, which canbe housed in gas enclosure 1002. Printing system 2002 can have printingsystem base 2100, which can be supported by at least two sets ofisolators such as isolator set 2110 that includes isolators 2110A and2110B of FIG. 3A and FIG. 3B. A Y-axis motion system can be mounted onprinting system base 2100 and can include Y-axis track 2350, supportedby Y-axis track support 2355. Substrate 2050 can be floatingly supportedby substrate floatation table 2200. Printing system base 2100 cansupport first riser 2120 and second riser 2122, upon which bridge 2130can be mounted. Printing system bridge 2130 can support first X-axiscarriage assembly 2301, upon which printhead assembly 2500 can bemounted, and second X-axis carriage assembly 2302, upon which cameraassembly 2550 can be mounted.

Additionally, gas enclosure system 500B of FIG. 6 can have auxiliaryenclosure 1330, depicted in phantom view, which can enclose printheadmanagement system 2701. Printing system 2000 of FIG. 1B depicts a gasenclosure having first auxiliary enclosure 1330 and second auxiliaryenclosure 1370, while in FIG. 6, auxiliary enclosure 1330 is indicated.As such, various embodiments of systems and methods of the presentteachings can have a gas enclosure with one auxiliary enclosure. Invarious embodiments of systems and methods of the present teachings, agas enclosure can have two auxiliary enclosures. Auxiliary enclosure1330 can be in flow communication with the printing system enclosure ofgas enclosure system 500B through printhead assembly opening 1342, andcan be sealably isolated from the remaining volume of gas enclosure1002, by way of non-limiting example, by docking first printheadassembly 2500 onto first printhead assembly docking gasket 1345. As willbe discussed in more detail subsequently herein, for various embodimentsof a multi-zone gas circulation and filtration system of the presentteachings, floor panel assembly 1341 (see also FIG. 1B) shown in phantomview in FIG. 6 can be configured as an auxiliary enclosure bafflestructure for directing the flow of air into auxiliary enclosure 1330.

Similarly to what has been described for FIG. 3A, various embodiments ofsystems and methods illustrated generally by FIG. 6 can have a firsttunnel enclosure section, and a second tunnel enclosure section, forexample, as first tunnel enclosure section 1200 and second tunnelenclosure section 1400 of FIG. 1A. In various embodiments, each tunnelenclosure section can have a tunnel circulation and filtration systemproviding cross-flow about the tunnel enclosure section. Variousembodiments of a tunnel circulation and filtration system of FIG. 6 canhave a tunnel circulation and filtration system providing cross-flow forboth the first tunnel enclosure section, as well as the second tunnelenclosure section. As illustrated generally in the schematic frontcross-section view of FIG. 6, various embodiments of tunnel circulationand filtration system 1500 can include inlet baffle 2140, which caninclude inlet baffle support 2142. Inlet baffle 2140, in conjunctionwith tunnel enclosure 1200, can direct the flow of gas across floatationtable 2200. Tunnel circulation and filtration system 1500 can includegas intake housing 1510, in which fan 1520, heat exchanger 1530, andfilter unit 1540 can be mounted in series. Filter unit 1540 can havetunnel circulation and filtration diffuser 1545 in series with filterunit 1540, as depicted in FIG. 6. In various embodiments, tunnelcirculation and filtration diffuser 1545 can be a perforated metallicplate for creating a controlled distribution of flow. Variousembodiments of tunnel circulation and filtration diffuser 1545 can be afiltration material having, for example, but not limited by, a porousstructure for creating a controlled distribution of flow. For variousembodiments of tunnel circulation and filtration diffuser 1545, gasflowing through the diffuser can provide for a desired controlledpressure drop, which can result in a controlled flow on an exit side ofa diffuser. For example, a diffuser can be designed to offset an unevenflow profile entering a flow-directing structure, such as a duct, abaffle or a plenum, leading to uniform flow on an exit side of adiffuser. Additionally, various embodiments of a diffuser according tothe present teachings can be designed for a specifically controllednon-uniform flow profile on an exit side of a diffuser.

For various embodiments of tunnel circulation and filtration system1500, fan 1520 and filter unit 1540 can be combined into a fan filterunit. Various embodiments of a tunnel circulation and filtration zonecan include outlet baffle 2141, which can include outlet baffle support2143. Outlet baffle 2141, in conjunction with tunnel enclosure 1200, candirect the flow of gas in a downward direction to be circulated acrossfloatation table 2200 and around a portion of a printing system housedin a first tunnel enclosure and second tunnel enclosure section (seealso FIG. 1B), thereby providing a cross-flow path in a first tunnelenclosure and second tunnel enclosure section. In that regard, variousembodiments of systems and methods of the present teachings can have afirst tunnel circulation and filtration zone, as well as a second tunnelcirculation and filtration zone. Various embodiments of tunnelcirculation and filtration system 1500 can provide filtered gas thatcirculates across the tunnel zone of a gas enclosure system.

For various systems and methods illustrated generally by FIG. 6, aspreviously discussed herein for FIG. 3A, FIG. 3B, as well as FIG. 4, atunnel circulation and filtration system, such as tunnel circulation andfiltration system 1500A can direct inert gas across substrate 2050. Forgas enclosure system 500A, inlet baffle 2140 and outlet baffle 2141, inconjunction with first tunnel enclosure section 1200 can be used todirect the flow of filtered gas laterally, so that gas is circulated ina cross-flow path through gas enclosure system 500A. Additionally, forvarious systems and methods illustrated generally by FIG. 6, aspreviously discussed herein for FIG. 4 and Table 3, the cross flow ofgas in a printing region proximal to a substrate can remove particlesthat may be generated by various printing system devices andapparatuses. As such, in addition to providing a low-particleenvironment throughout a tunnel enclosure section, the cross flow of gasin a printing region proximal to a substrate provides for a low-particleenvironment in a printing area proximal to a substrate.

FIG. 7A is a schematic top section view of gas enclosure system 500B,depicting various embodiments of a tunnel circulation and filtrationzone, as well various embodiments of a bridge circulation and filtrationzone. The section is taken through gas enclosure 1002, at about thelevel of floor panel assembly 1341 (see also FIG. 1B), which can beconfigured as an auxiliary enclosure baffle structure for directing theflow of air into auxiliary enclosure 1330, as indicated in FIG. 7A.Auxiliary enclosure baffle structure 1341 can have opening 1342 ofauxiliary enclosure 1330 (see FIG. 1B), around which gasket 1345 can bemounted. As previously discussed herein, various embodiments of systemsand methods of the present teachings can have a gas enclosure with oneauxiliary enclosure. Additionally, for various embodiments of systemsand methods of the present teachings, a gas enclosure can have twoauxiliary enclosures. In the schematic rending of FIG. 7A, tunnel crossflow circulation path 20 is depicted for first tunnel enclosure section1200 and second tunnel enclosure section 1400 of gas enclosure system500B. Cross flow circulation path 20 of FIG. 7A is depicted as a flowpath circulating gas around a printing system, which can includefloatation table 2200 (see FIG. 1B). According to various embodiments ofa multi-zone circulation and filtration system of the present teachings,first tunnel circulation and filtration system 1500A can be positionedapproximately mid-way in first tunnel enclosure section 1200. Forvarious embodiments of systems and methods of the present teachings, gasenclosure system 500B may utilize a single tunnel circulation andfiltration system. As depicted in FIG. 6, various systems and methods ofthe present teachings can utilize two tunnel circulation and filtrationsystems, and can include second tunnel circulation and filtration system1500B, which can be positioned approximately mid-way in second tunnelenclosure section 1400.

Gas enclosure system 500B of FIG. 7A can have first riser 2120 andsecond riser 2122 for supporting bridge 2130 (see FIG. 6), upon whichcarriage assembly 2301 can be mounted. Bridge circulation and filtrationsystem 1550B of gas enclosure system 500B of FIG. 7A can have bridgeenclosure section first return duct 1566 and bridge enclosure sectionsecond return duct 1568, which can direct gas circulating into a bridgeenclosure section output plenum 1568. Bridge enclosure section outputplenum 1568 can have bridge circulation and filtration diffuser 1569. Invarious embodiments, bridge circulation and filtration diffuser 1569 canbe a perforated metallic plate for creating a controlled distribution offlow. Various embodiments of bridge circulation and filtration diffuser1569 can be a filtration material having, for example, but not limitedby, a porous structure for creating a controlled distribution of flow.For various embodiments of bridge circulation and filtration diffuser1569, gas flowing through the diffuser can provide for a desiredcontrolled pressure drop, which can result in a controlled flow on anexit side of a diffuser. For example, a diffuser can be designed tooffset an uneven flow profile entering a flow-directing structure, suchas a duct, a baffle or a plenum, leading to uniform flow on an exit sideof a diffuser. Additionally, various embodiments of a diffuser accordingto the present teachings can be designed for a specifically controllednon-uniform flow profile on an exit side of a diffuser. On the wall ofthe bridge enclosure section 1300 opposing the wall on which bridgecirculation and filtration diffuser 1569 is located, a bridge enclosuresection baffle can be mounted (not shown), which in conjunction with thebridge enclosure wall, can direct gas up around a printing system bridgeand related apparatuses and devices. In that regard, various embodimentsof a bridge circulation and filtration system of FIG. 7A can have flowdirecting structures such as a first and second return duct in flowcommunication with an output plenum with a flow diffuser, which candirect a flow of gas towards a baffle that can direct the gas up andaround a printing system bridge and related apparatuses and devices andaway from a substrate in a printing region.

As depicted in FIG. 7B for gas enclosure system 500B, bridge enclosuresection baffle 2157 can direct gas up and around printhead assembly2500. Bridge circulation and filtration system 1550B can have bridgecirculation flow path 40, which can draw filtered gas in an upwarddirection around, for example, X-axis carriage assembly 2301. Bridgecirculation and filtration system 1550B can include service bundlehousing exhaust system 2400, which can include service bundle housing2410, as well as bridge enclosure section exhaust duct 2450, which canexhaust service bundle housing 2410, and generally the bridge enclosuresection, as indicated by flow path 40. Bridge enclosure section exhaustduct 2450 can have bridge enclosure section exhaust duct diffuser 2455,which can provide for a desired controlled pressure drop that can resultin a controlled flow into bridge enclosure section exhaust duct 2450. Invarious embodiments, bridge enclosure section exhaust duct diffuser 2455can be a perforated metallic plate for creating a controlleddistribution of flow. Various embodiments of bridge enclosure sectionexhaust duct diffuser 2455 can be a filtration material having, forexample, but not limited by, a porous structure for creating acontrolled distribution of flow. For various embodiments of bridgeenclosure section exhaust duct diffuser 2455, gas flowing through thediffuser can provide for a desired controlled pressure drop, which canresult in a controlled flow on an exit side of a diffuser. For example,a diffuser can be designed to offset an uneven flow profile entering aflow-directing structure, such as a duct, a baffle or a plenum, leadingto uniform flow on an exit side of a diffuser. Additionally, variousembodiments of a diffuser according to the present teachings can bedesigned for a specifically controlled non-uniform flow profile on anexit side of a diffuser.

Bridge circulation and filtration system 1550B can include bridgecirculation and filtration system intake duct 1560, which can be in flowcommunication with bridge enclosure section exhaust duct 2450. Bridgecirculation and filtration system 1550A can include fan 1570, heatexchanger 1580, and filter 1590, which can be mounted within bridgecirculation and filtration system intake duct 1560. For variousembodiments of bridge circulation and filtration system 1550A, fan 1570and filter unit 1590 can be combined into a fan filter unit. Bridgecirculation and filtration system intake duct 1560 can be in flowcommunication with bridge circulation and filtration system return firstduct 1564 and bridge circulation and filtration system return secondduct 1566. Bridge circulation and filtration system return first duct1564 and bridge circulation and filtration system return second duct1566 can be in flow communication with bridge enclosure section outputplenum 1568 as indicated in FIG. 7B. Circulating gas can then flowthrough bridge circulation and filtration diffuser 1569, and can then bedirected towards bridge enclosure section baffle 2157, completing bridgecirculation flow path 40 thereby.

According to the present teachings, as depicted and illustratedgenerally for FIGS. 3A-7B, various embodiments of a multi-zone gascirculation and filtration system can effectively remove airborneparticulate matter in various sections of a gas enclosure, such as atunnel enclosure section and a bridge enclosure section. Additionally,various embodiments of a multi-zone gas circulation and filtrationsystem of the present teachings can remove particulate matter generatedproximal to a substrate during, for example, a printing process byutilizing various embodiments of a tunnel circulation and filtrationsystem together with a bridge circulation and filtration system.

FIG. 8 is a schematic diagram showing a gas enclosure system 501.Various embodiments of a gas enclosure system 501 according to thepresent teachings can comprise gas enclosure assembly 1003 for housing aprinting system, gas purification loop 3130 in fluid communication gasenclosure assembly 1003, and at least one thermal regulation system3140. Additionally, various embodiments of gas enclosure system 501 canhave pressurized inert gas recirculation system 3000, which can supplyinert gas for operating various devices, such as a substrate floatationtable for an OLED printing system. Various embodiments of a pressurizedinert gas recirculation system 3000 can utilize a compressor, a blowerand combinations of the two as sources for various embodiments ofpressurized inert gas recirculation system 3000, as will be discussed inmore detail subsequently herein. Additionally, gas enclosure system 501can have a circulation and filtration system internal to gas enclosuresystem 501 (not shown).

As depicted in, for example, FIG. 3A, FIG. 3B, FIG. 5A, FIG. 5B, FIG. 6,FIG. 7A and FIG. 7B, for various embodiments of a gas enclosure assemblyaccording to the present teachings, the design of a two zone tunnelcirculation and filtration system, and a bridge circulation andfiltration system can separate the inert gas circulated through gaspurification loop 3130 from the inert gas that is continuously filteredand circulated internally for various embodiments of a gas enclosureassembly. Gas purification loop 3130 includes gas purification outletline 3131 from gas enclosure assembly 1003, to a solvent removalcomponent 3132 and then to gas purification system 3134. Inert gaspurified of solvent and other reactive gas species, such as oxygen,ozone, and water vapor, are then returned to gas enclosure assembly 1003through gas enclosure gas purification inlet line 3133, which receivespurified gas from a gas purification outlet line. Gas purification loop3130 may also include appropriate conduits and connections, and sensors,for example, oxygen, ozone, water vapor and solvent vapor sensors. A gascirculating unit, such as a fan, blower or motor and the like, can beseparately provided or integrated, for example, in gas purificationsystem 3134, to circulate gas through gas purification loop 3130.According to various embodiments of a gas enclosure assembly, thoughsolvent removal system 3132 and gas purification system 3134 are shownas separate units in the schematic shown in FIG. 8, solvent removalsystem 3132 and gas purification system 3134 can be housed together as asingle purification unit.

Gas purification loop 3130 of FIG. 8 can have solvent removal system3132 placed upstream of gas purification system 3134, so that inert gascirculated from gas enclosure assembly 1003 passes through solventremoval system 3132 via gas purification outlet line 3131. According tovarious embodiments, solvent removal system 3132 may be a solventtrapping system based on adsorbing solvent vapor from an inert gaspassing through solvent removal system 3132 of FIG. 8. A bed or beds ofa sorbent, for example, but not limited by, such as activated charcoal,molecular sieves, and the like, may effectively remove a wide variety oforganic solvent vapors. For various embodiments of a gas enclosuresystem cold trap technology may be employed to remove solvent vapors insolvent removal system 3132. As previously discussed herein, for variousembodiments of a gas enclosure system according to the presentteachings, sensors, such as oxygen, ozone, water vapor and solvent vaporsensors, may be used to monitor the effective removal of such speciesfrom inert gas continuously circulating through a gas enclosure system,such as gas enclosure system 501 of FIG. 8. Various embodiments of asolvent removal system can indicate when sorbent, such as activatedcarbon, molecular sieves, and the like, has reached capacity, so thatthe bed or beds of sorbent can be regenerated or replaced. Regenerationof a molecular sieve can involve heating the molecular sieve, contactingthe molecular sieve with a forming gas, a combination thereof, and thelike. Molecular sieves configured to trap various species, includingoxygen, ozone, water vapor, and solvents, can be regenerated by heatingand exposure to a forming gas that comprises hydrogen, for example, aforming gas comprising about 96% nitrogen and 4% hydrogen, with saidpercentages being by volume or by weight. Physical regeneration ofactivated charcoal can be done using a similar procedure of heatingunder an inert environment.

Any suitable gas purification system can be used for gas purificationsystem 3134 of gas purification loop 3130 of FIG. 8. Gas purificationsystems available, for example, from MBRAUN Inc., of Statham, N.H., orInnovative Technology of Amesbury, Mass., may be useful for integrationinto various embodiments of a gas enclosure assembly according to thepresent teachings. Gas purification system 3134 can be used to purifyone or more inert gases in gas enclosure system 501, for example, topurify the entire gas atmosphere within a gas enclosure assembly. Aspreviously discussed herein, in order to circulate gas through gaspurification loop 3130, gas purification system 3134 can have a gascirculating unit, such as a fan, blower or motor, and the like. In thatregard, a gas purification system can be selected depending on thevolume of the enclosure, which can define a volumetric flow rate formoving an inert gas through a gas purification system. For variousembodiments of gas enclosure system having a gas enclosure assembly witha volume of up to about 4 m³; a gas purification system that can moveabout 84 m³/h can be used. For various embodiments of gas enclosuresystem having a gas enclosure assembly with a volume of up to about 10m³; a gas purification system that can move about 155 m³/h can be used.For various embodiments of a gas enclosure assembly having a volume ofbetween about 52-114 m³, more than one gas purification system may beused.

Any suitable gas filters or purifying devices can be included in the gaspurification system 3134 of the present teachings. In some embodiments,a gas purification system can comprise two parallel purifying devices,such that one of the devices can be taken off line for maintenance andthe other device can be used to continue system operation withoutinterruption. In some embodiments, for example, the gas purificationsystem can comprise one or more molecular sieves. In some embodiments,the gas purification system can comprise at least a first molecularsieve, and a second molecular sieve, such that, when one of themolecular sieves becomes saturated with impurities, or otherwise isdeemed not to be operating efficiently enough, the system can switch tothe other molecular sieve while regenerating the saturated ornon-efficient molecular sieve. A control unit can be provided fordetermining the operational efficiency of each molecular sieve, forswitching between operation of different molecular sieves, forregenerating one or more molecular sieves, or for a combination thereof.As previously discussed herein, molecular sieves may be regenerated andreused.

Thermal regulation system 3140 of FIG. 8 can include at least onechiller 3142, which can have fluid outlet line 3141 for circulating acoolant into a gas enclosure assembly, and fluid inlet line 3143 forreturning the coolant to the chiller. An at least one fluid chiller 3142can be provided for cooling the gas atmosphere within gas enclosuresystem 501. For various embodiments of a gas enclosure system of thepresent teachings, fluid chiller 3142 delivers cooled fluid to heatexchangers within the enclosure, where inert gas is passed over afiltration system internal the enclosure. At least one fluid chiller canalso be provided with gas enclosure system 501 to cool heat evolvingfrom an apparatus enclosed within gas enclosure system 501. For example,but not limited by, at least one fluid chiller can also be provided forgas enclosure system 501 to cool heat evolving from an OLED printingsystem. Thermal regulation system 3140 can comprise heat-exchange orPeltier devices and can have various cooling capacities. For example,for various embodiments of a gas enclosure system, a chiller can providea cooling capacity of from between about 2 kW to about 20 kW. Variousembodiments of a gas enclosure system can have a plurality of fluidchillers that can chill one or more fluids. In some embodiments, thefluid chillers can utilize a number of fluids as coolant, for example,but not limited by, water, anti-freeze, a refrigerant, and a combinationthereof as a heat exchange fluid. Appropriate leak-free, lockingconnections can be used in connecting the associated conduits and systemcomponents.

As previously discussed herein, the present teachings disclose variousembodiments of a gas enclosure system that can include a printing systemenclosure defining a first volume and an auxiliary enclosure defining asecond volume. Various embodiments of a gas enclosure system can have anauxiliary enclosure that can be constructed as a sealable section of gasenclosure assembly. According to systems and methods of the presentteachings, an auxiliary enclosure can be sealable isolated from aprinting system enclosure, and can be opened to an environment externala gas enclosure assembly without exposing a printing system enclosure tothe external environment. Such physical isolation of an auxiliaryenclosure to perform, for example, but not limited by, various printheadmanagement procedures, can be done to eliminate or minimize the exposureof a printing system enclosure to contamination, such as air and watervapor and various organic vapors, as well as particulate contamination.Various printhead management procedures that can include measurement andmaintenance procedures on a printhead assembly can be done with littleor no interruption of a printing process, thereby minimizing oreliminating gas enclosure system downtime.

For a gas enclosure system having a printing system enclosure defining afirst volume and an auxiliary enclosure defining a second volume, bothvolumes can be readily integrated with gas circulation, filtration andpurification components to form a gas enclosure system that can sustainan inert, substantially low-particle environment for processes requiringsuch an environment with little or no interruption of a printingprocess. According to various systems and methods of the presentteachings, a printing system enclosure may be introduced to a level ofcontamination that is sufficiently low that a purification system canremove the contamination before it can affect a printing process.Various embodiments of an auxiliary enclosure can be a substantiallysmaller volume of the total volume of a gas enclosure assembly and canbe readily integrated with gas circulation, filtration and purificationcomponents to form an auxiliary enclosure system that can rapidlyrecover an inert, of a low-particle environment after exposure to anexternal environment, thereby providing little or no interruption of aprinting process.

According to systems and methods of the present teachings, variousembodiments of a printing system enclosure and an auxiliary enclosureconstructed as sections of a gas enclosure assembly can be constructedin a fashion to provide for separately-functioning frame member assemblysections. Gas enclosure system 502 of FIG. 9 can have all elementsdisclosed, for example, for gas enclosure system 500A of FIG. 3A andFIG. 3B, and gas enclosure 501 of FIG. 8. Additionally, gas enclosuresystem 502 of FIG. 9, can have first gas enclosure assembly section1004-S1 defining a first volume of gas enclosure assembly 1004 andsecond gas enclosure assembly section 1004-S2 defining a second volumeof gas enclosure assembly 1004. If all valves, V₁, V₂, V₃ and V₄ areopened, then gas purification loop 3130 operates essentially aspreviously described for gas enclosure assembly and system 1003 of FIG.9. With closure of V₃ and V₄, only first gas enclosure assembly section1004-S1 is in fluid communication with gas purification loop 3130. Thisvalve state may be used, for example, but not limited by, when secondgas enclosure assembly section 1004-S2 is sealably closed and therebyisolated from first gas enclosure assembly section 1004-S1 duringvarious measurement and maintenances procedure requiring that second gasenclosure assembly section 1004-S2 be opened to the atmosphere. Withclosure of V₁ and V₂, only second gas enclosure assembly section 1004-S2is in fluid communication with gas purification loop 3130. This valvestate may be used, for example, but not limited by, during recovery ofsecond gas enclosure assembly section 1004-S2 after the section has beenopened to the atmosphere. As previously discussed herein for the presentteachings related to FIG. 9, the requirements for gas purification loop3130 are specified with respect to the total volume of gas enclosureassembly 1003. Therefore, by devoting the resources of a gaspurification system to the recovery of a gas enclosure assembly section,such as second gas enclosure assembly section 1004-S2, which is depictedfor gas enclosure system 502 of FIG. 9 to be significantly less involume than the total volume of gas enclosure 1004, the recovery timecan be substantially reduced.

Additionally, various embodiments of an auxiliary enclosure can bereadily integrated with a dedicated set of environmental regulationsystem components, such as lighting, gas circulation and filtration, gaspurification, and thermostating components. In that regard, variousembodiments of a gas enclosure system that include an auxiliaryenclosure that can be sealably isolated as a section of gas enclosureassembly can have a controlled environment that is set to be uniformwith a first volume defined by a gas enclosure assembly housing aprinting system. Further, various embodiments of a gas enclosure systemincluding an auxiliary enclosure that can be sealably isolated as asection of gas enclosure assembly can have a controlled environment thatis set to be different than the controlled environment of a first volumedefined by a gas enclosure assembly housing a printing system.

FIGS. 10A and 10B illustrate generally examples of a gas enclosuresystem for integrating and controlling non-reactive gas and clean dryair (CDA) sources such as can be used to establish the controlledenvironment referred to in other examples described elsewhere herein,and such as can include a supply of pressurized gas for use with afloatation table. FIGS. 11A and 11B illustrate generally examples of agas enclosure system for integrating and controlling non-reactive gasand clean dry air (CDA) sources such as can be used to establish thecontrolled environment referred to in other examples described elsewhereherein, and such as can include a blower loop to provide, for example,pressurized gas and at least partial vacuum for use with a floatationtable. FIG. 11C illustrates generally a further example of a system forintegrating and controlling one or more gas or air sources, such as toestablish floatation control zones included as a portion of a floatationconveyance system.

Recalling, various embodiments of a gas enclosure assembly utilized inembodiments of a gas enclosure system of the present teachings can beconstructed in a contoured fashion that minimizes the internal volume ofa gas enclosure assembly, and at the same time optimizes the workingvolume for accommodating various footprints of OLED printing systemsdesigns. For example, various embodiments of a contoured gas enclosureassembly according to the present teachings can have a gas enclosurevolume of between about 6 m³ to about 95 m³ for various embodiments of agas enclosure assembly of the present teachings covering, for example,substrate sizes from Gen 3.5 to Gen 10. Various embodiments of acontoured gas enclosure assembly according to the present teachings canhave a gas enclosure volume of, for example, but not limited by, ofbetween about 15 m³ to about 30 m³, which might be useful for OLEDprinting of, for example, Gen 5.5 to Gen 8.5 substrate sizes. Variousembodiments of an auxiliary enclosure can be constructed as a section ofgas enclosure assembly and readily integrated with gas circulation andfiltration, as well as purification components to form a gas enclosuresystem that can sustain an inert, substantially low-particle environmentfor processes requiring such an environment.

As shown in FIG. 10A and FIG. 11A, various embodiments of a gasenclosure system can include a pressurized inert gas recirculationsystem 3000. Various embodiments of a pressurized inert gasrecirculation loop can utilize a compressor, a blower and combinationsthereof.

According to the present teachings, several engineering challenges wereaddressed in order to provide for various embodiments of a pressurizedinert gas recirculation system in a gas enclosure system. First, undertypical operation of a gas enclosure system without a pressurized inertgas recirculation system, a gas enclosure system can be maintained at aslightly positive internal pressure relative to an external pressure inorder to safeguard against outside gas or air from entering the interiorshould any leaks develop in a gas enclosure system. For example, undertypical operation, for various embodiments of a gas enclosure system ofthe present teachings, the interior of a gas enclosure system can bemaintained at a pressure relative to the surrounding atmosphere externalto the enclosure system, for example, of at least 2 mbarg, for example,at a pressure of at least 4 mbarg, at a pressure of at least 6 mbarg, ata pressure of at least 8 mbarg, or at a higher pressure.

Maintaining a pressurized inert gas recirculation system within a gasenclosure system can be challenging, as it presents a dynamic andongoing balancing act regarding maintaining a slight positive internalpressure of a gas enclosure system, while at the same time continuouslyintroducing pressurized gas into a gas enclosure system. Further,variable demand of various devices and apparatuses can create anirregular pressure profile for various gas enclosure assemblies andsystems of the present teachings. Maintaining a dynamic pressure balancefor a gas enclosure system held at a slight positive pressure relativeto the external environment under such conditions can provide for theintegrity of an ongoing OLED printing process. For various embodimentsof a gas enclosure system, a pressurized inert gas recirculation systemaccording to the present teachings can include various embodiments of apressurized inert gas loop that can utilize at least one of acompressor, an accumulator, and a blower, and combinations thereof.Various embodiments of a pressurized inert gas recirculation system thatinclude various embodiments of a pressurized inert gas loop can have aspecially designed pressure-controlled bypass loop that can provideinternal pressure of an inert gas in a gas enclosure system of thepresent teachings at a stable, defined value. In various embodiments ofa gas enclosure system, a pressurized inert gas recirculation system canbe configured to recirculate pressurized inert gas via apressure-controlled bypass loop when a pressure of an inert gas in anaccumulator of a pressurized inert gas loop exceeds a pre-set thresholdpressure. The threshold pressure can be, for example, within a rangefrom between about 25 psig to about 200 psig, or more specificallywithin a range of between about 75 psig to about 125 psig, or morespecifically within a range from between about 90 psig to about 95 psig.In that regard, a gas enclosure system of the present teachings having apressurized inert gas recirculation system with various embodiments of aspecially designed pressure-controlled bypass loop can maintain abalance of having a pressurized inert gas recirculation system in anhermetically sealed gas enclosure.

According to the present teachings, various devices and apparatuses canbe disposed in the interior of a gas enclosure system and in fluidcommunication with various embodiments of a pressurized inert gasrecirculation system. For various embodiments of a gas enclosure andsystem of the present teachings, the use of various pneumaticallyoperated devices and apparatuses can provide low-particle generatingperformance, as well as being low maintenance. Exemplary devices andapparatuses that can be disposed in the interior of a gas enclosuresystem and in fluid communication with various pressurized inert gasloops can include, for example, but not limited by, one or more of apneumatic robot, a substrate floatation table, an air bearing, an airbushing, a compressed gas tool, a pneumatic actuator, and combinationsthereof. A substrate floatation table, as well as air bearings can beused for various aspects of operating an OLED printing system inaccordance with various embodiments of a gas enclosure system of thepresent teachings. For example, a substrate floatation table utilizingair-bearing technology can be used to transport a substrate intoposition in a printhead chamber, as well as to support a substrateduring an OLED printing process.

For example, as shown in FIG. 10A and FIG. 11A, various embodiments ofgas enclosure system 503A and gas enclosure system 504A can haveexternal gas loop 3200 for integrating and controlling inert gas source3201 and clean dry air (CDA) source 3203 for use in various aspects ofoperation of gas enclosure system 503A and gas enclosure system 504A.Gas enclosure system 503A and gas enclosure system 504A can also includevarious embodiments of an internal particle filtration and gascirculation system, as well as various embodiments of an external gaspurification system, as previously described. Such embodiments of a gasenclosure system can include a gas purification system for purifyingvarious reactive species from an inert gas. Some commonly usednon-limiting examples of an inert gas can include nitrogen, any of thenoble gases, and any combination thereof. Various embodiments of a gaspurification system according to the present teachings can maintainlevels for each species of various reactive species, including variousreactive atmospheric gases, such as water vapor, oxygen and ozone, aswell as organic solvent vapors at 100 ppm or lower, for example, at 10ppm or lower, at 1.0 ppm or lower, or at 0.1 ppm or lower. In additionto external loop 3200 for integrating and controlling inert gas source3201 and CDA source 3203, gas enclosure system 503A and gas enclosuresystem 504A can have compressor loop 3250, which can supply inert gasfor operating various devices and apparatuses that can be disposed inthe interior of gas enclosure system 503A and gas enclosure system 504A.

Compressor loop 3250 of FIG. 10A can include compressor 3262, firstaccumulator 3264 and second accumulator 3268, which are configured to bein fluid communication. Compressor 3262 can be configured to compressinert gas withdrawn from gas enclosure assembly 1005 to a desiredpressure. An inlet side of compressor loop 3250 can be in fluidcommunication with gas enclosure assembly 1005 via gas enclosureassembly outlet 3252 through line 3254, having valve 3256 and checkvalve 3258. Compressor loop 3250 can be in fluid communication with gasenclosure assembly 1005 on an outlet side of compressor loop 3250 viaexternal gas loop 3200. Accumulator 3264 can be disposed betweencompressor 3262 and the junction of compressor loop 3250 with externalgas loop 3200 and can be configured to generate a pressure of 5 psig orhigher. Second accumulator 3268 can be in compressor loop 3250 forproviding dampening fluctuations due to compressor piston cycling atabout 60 Hz. For various embodiments of compressor loop 3250, firstaccumulator 3264 can have a capacity of between about 80 gallons toabout 160 gallons, while second accumulator can have a capacity ofbetween about 30 gallons to about 60 gallons. According to variousembodiments of gas enclosure system 503A, compressor 3262 can be a zeroingress compressor. Various types of zero ingress compressors canoperate without leaking atmospheric gases into various embodiments of agas enclosure system of the present teachings. Various embodiments of azero ingress compressor can be run continuously, for example, during anOLED printing process utilizing the use of various devices andapparatuses requiring compressed inert gas.

Accumulator 3264 can be configured to receive and accumulate compressedinert gas from compressor 3262. Accumulator 3264 can supply thecompressed inert gas as needed in gas enclosure assembly 1005. Forexample, accumulator 3264 can provide gas to maintain pressure forvarious components of gas enclosure assembly 1005, such as, but notlimited by, one or more of a pneumatic robot, a substrate floatationtable, an air bearing, an air bushing, a compressed gas tool, apneumatic actuator, and combinations thereof. As shown in FIG. 10A forgas enclosure system 503A, gas enclosure assembly 1005 can have an OLEDprinting system 2000 enclosed therein. As schematically depicted in FIG.10A, inkjet printing system 2000 can be supported by printing systembase 2100, which can be a granite stage. Printing system base 2100 cansupport a substrate support apparatus, such as a chuck, for example, butnot limited by, a vacuum chuck, a substrate floatation chuck havingpressure ports, and a substrate floatation chuck having vacuum andpressure ports. In various embodiments of the present teachings, asubstrate support apparatus can be a substrate floatation table, such assubstrate floatation table 2200 indicated in FIG. 10A. Substratefloatation table 2200 can be used for the frictionless support of asubstrate. In addition to a low-particle generating floatation table,for frictionless Y-axis conveyance of a substrate, printing system 2000can have a Y-axis motion system utilizing air bushings.

Additionally, printing system 2000 can have at least one X,Z-axiscarriage assembly with motion control provided by a low-particlegenerating X-axis air bearing assembly. Various components of alow-particle generating motion system, such as an X-axis air bearingassembly, can be used in place of, for example, variousparticle-generating linear mechanical bearing systems. For variousembodiments of a gas enclosure and system of the present teachings, theuse of a variety of pneumatically operated devices and apparatuses canprovide low-particle generating performance, as well as being lowmaintenance. Compressor loop 3250 can be configured to continuouslysupply pressurized inert gas to various devices and apparatuses of gasenclosure system 503A. In addition to a supply of pressurized inert gas,substrate floatation table 2200 of inkjet printing system 2000, whichutilizes air bearing technology, also utilizes vacuum system 3270, whichis in communication with gas enclosure assembly 1005 through line 3272when valve 3274 is in an open position.

A pressurized inert gas recirculation system according to the presentteachings can have pressure-controlled bypass loop 3260 as shown in FIG.10A for compressor loop 3250, which acts to compensate for variabledemand of pressurized gas during use, thereby providing dynamic balancefor various embodiments of a gas enclosure system of the presentteachings. For various embodiments of a gas enclosure system accordingto the present teachings, a bypass loop can maintain a constant pressurein accumulator 3264 without disrupting or changing the pressure inenclosure 1005. Bypass loop 3260 can have first bypass inlet valve 3261on an inlet side of bypass loop, which is closed unless bypass loop 3260is used. Bypass loop 3260 can also have back pressure regulator 3266,which can be used when second valve 3263 is closed. Bypass loop 3260 canhave second accumulator 3268 disposed at an outlet side of bypass loop3260. For embodiments of compressor loop 3250 utilizing a zero ingresscompressor, bypass loop 3260 can compensate for small excursions ofpressure that can occur over time during use of a gas enclosure system.Bypass loop 3260 can be in fluid communication with compressor loop 3250on an inlet side of bypass loop 3260 when bypass inlet valve 3261 is inan opened position. When bypass inlet valve 3261 is opened, inert gasshunted through bypass loop 3260 can be recirculated to the compressorif inert gas from compressor loop 3250 is not in demand within theinterior of gas enclosure assembly 1005. Compressor loop 3250 isconfigured to shunt inert gas through bypass loop 3260 when a pressureof the inert gas in accumulator 3264 exceeds a pre-set thresholdpressure. A pre-set threshold pressure for accumulator 3264 can be frombetween about 25 psig to about 200 psig at a flow rate of at least about1 cubic feet per minute (cfm), or from between about 50 psig to about150 psig at a flow rate of at least about 1 cubic feet per minute (cfm),or from between about 75 psig to about 125 psig at a flow rate of atleast about 1 cubic feet per minute (cfm) or between about 90 psig toabout 95 psig at a flow rate of at least about 1 cubic feet per minute(cfm).

Various embodiments of compressor loop 3250 can utilize a variety ofcompressors other than a zero ingress compressor, such as a variablespeed compressor or a compressor that can be controlled to be in eitheran on or off state. As previously discussed herein, a zero ingresscompressor ensures that no atmospheric reactive species can beintroduced into a gas enclosure system. As such, any compressorconfiguration preventing atmospheric reactive species from beingintroduced into a gas enclosure system can be utilized for compressorloop 3250. According to various embodiments, compressor 3262 of gasenclosure system 503A can be housed in, for example, but not limited by,an hermetically-sealed housing. The housing interior can be configuredin fluid communication with a source of inert gas, for example, the sameinert gas that forms the inert gas atmosphere for gas enclosure assembly1005. For various embodiments of compressor loop 3250, compressor 3262can be controlled at a constant speed to maintain a constant pressure.In other embodiments of compressor loop 3250 not utilizing a zeroingress compressor, compressor 3262 can be turned off when a maximumthreshold pressure is reached, and turned on when a minimum thresholdpressure is reached.

In FIG. 11A for gas enclosure system 504A, blower loop 3280 utilizingvacuum blower 3290 is shown for the operation of substrate floatationtable 2200 of inkjet printing system 2000, which are housed in gasenclosure assembly 1005. As previously discussed herein for compressorloop 3250, blower loop 3280 can be configured to continuously supplypressurized inert gas to a substrate floatation table 2200 of printingsystem 2000.

Various embodiments of a gas enclosure system that can utilize apressurized inert gas recirculation system can have various loopsutilizing a variety of pressurized gas sources, such as at least one ofa compressor, a blower, and combinations thereof. In FIG. 11A for gasenclosure system 504A, compressor loop 3250 can be in fluidcommunication with external gas loop 3200, which can be used for thesupply of inert gas for high consumption manifold 3225, as well as lowconsumption manifold 3215. For various embodiments of a gas enclosuresystem according to the present teachings as shown in FIG. 11A for gasenclosure system 504A, high consumption manifold 3225 can be used tosupply inert gas to various devices and apparatuses, such as, but notlimited by, one or more of a substrate floatation table, a pneumaticrobot, an air bearing, an air bushing, and a compressed gas tool, andcombinations thereof. For various embodiments of a gas enclosure systemaccording to the present teachings, low consumption 3215 can be used tosupply inert gas to various apparatuses and devises, such as, but notlimited by, one or more of an isolator, and a pneumatic actuator, andcombinations thereof.

For various embodiments of gas enclosure system 504A of FIG. 11A, blowerloop 3280 can be utilized to supply pressurized inert gas to variousembodiments of substrate floatation table 2200, while compressor loop3250; in fluid communication with external gas loop 3200, can beutilized to supply pressurized inert gas to, for example, but notlimited by, one or more of a pneumatic robot, an air bearing, an airbushing, and a compressed gas tool, and combinations thereof. Inaddition to a supply of pressurized inert gas, substrate floatationtable 2200 of OLED inkjet printing system 2000, which utilizes airbearing technology, also utilizes blower vacuum 3290, which is incommunication with gas enclosure assembly 1005 through line 3292 whenvalve 3294 is in an open position. Housing 3282 of blower loop 3280 canmaintain first blower 3284 for supplying a pressurized source of inertgas to substrate floatation table 2200, and second blower 3290, actingas a vacuum source for substrate floatation table 2200, which is housedin an inert gas environment in gas enclosure assembly 1005. Attributesthat can make blowers suitable for use as a source of either pressurizedinert gas or vacuum for various embodiments a substrate floatation tableinclude, for example, but not limited by, that they have highreliability; making them low maintenance, have variable speed control,and have a wide range of flow volumes; various embodiments capable ofproviding a volume flow of between about 100 m³/h to about 2,500 m³/h.Various embodiments of blower loop 3280 additionally can have firstisolation valve 3283 at an inlet end of blower loop 3280, as well ascheck valve 3285 and a second isolation valve 3287 at an outlet end ofblower loop 3280. Various embodiments of blower loop 3280 can haveadjustable valve 3286, which can be, for example, but not limited by, agate, butterfly, needle or ball valve, as well as heat exchanger 3288for maintaining inert gas from blower loop 3280 to substrate floatationtable 2200 at a defined temperature.

FIG. 11A depicts external gas loop 3200, also shown in FIG. 10A, forintegrating and controlling inert gas source 3201 and clean dry air(CDA) source 3203 for use in various aspects of operation of gasenclosure system 503A of FIG. 10A and gas enclosure system 504A of FIG.11A. External gas loop 3200 of FIG. 10A and FIG. 11A can include atleast four mechanical valves. These valves comprise first mechanicalvalve 3202, second mechanical valve 3204, third mechanical valve 3206,and fourth mechanical valve 3208. These various valves are located atpositions in various flow lines that allow control of both an inert gasand an air source such as clean dry air (CDA). According to the presentteachings, an inert gas may be any gas that does not undergo a chemicalreaction under a defined set of conditions. Some commonly usednon-limiting examples of an inert gas can include nitrogen, any of thenoble gases, and any combination thereof. From a house inert gas source3201, a house inert gas line 3210 extends. House inert gas line 3210continues to extend linearly as low consumption manifold line 3212,which is in fluid communication with low consumption manifold 3215. Across-line first section 3214 extends from a first flow juncture 3216,which is located at the intersection of house inert gas line 3210, lowconsumption manifold line 3212, and cross-line first section 3214.Cross-line first section 3214 extends to a second flow juncture 3218. Acompressor inert gas line 3220 extends from accumulator 3264 ofcompressor loop 3250 and terminates at second flow juncture 3218. A CDAline 3222 extends from a CDA source 3203 and continues as highconsumption manifold line 3224, which is in fluid communication withhigh consumption manifold 3225. A third flow juncture 3226 is positionedat the intersection of a cross-line second section 3228, clean dry airline 3222, and high consumption manifold line 3224. Cross-line secondsection 3228 extends from second flow juncture 3218 to third flowjuncture 3226. Various components that are high consumption can besupplied CDA during maintenance, by means high consumption manifold3225. Isolating the compressor using valves 3204, 3208, and 3230 canprevent reactive species, such as oxygen, ozone and water vapor fromcontaminating an inert gas within the compressor and accumulator.

By contrast with FIGS. 10A and 11A, FIGS. 10B and 11B illustrategenerally a configuration wherein a pressure of gas inside the gasenclosure assembly 1005 can be maintained within a desired or specifiedrange, such as using a valve coupled to a pressure monitor, P, where thevalve allows gas to be exhausted to another enclosure, system, or aregion surrounding the gas enclosure assembly 1005 using informationobtained from the pressure monitor. Such gas can be recovered andre-processed as in other examples described herein. As mentioned above,such regulation can assist in maintaining a slight positive internalpressure of a gas enclosure system, because pressurized gas is alsocontemporaneously introduced into the gas enclosure system. Variabledemand of various devices and apparatuses can create an irregularpressure profile for various gas enclosure assemblies and systems of thepresent teachings. Accordingly, the approach shown in FIGS. 10B and 11Bfor gas enclosure systems 503B and 504B, respectively, can be used inaddition or instead of other approaches described herein such as toassist in maintaining a dynamic pressure balance for a gas enclosuresystem held at a slight positive pressure relative to the environmentsurrounding the enclosure.

FIG. 11C illustrates generally a further example of printing system 504Cfor integrating and controlling one or more gas or air sources, such asto establish floatation control zones included as a portion of afloatation conveyance system. Similar to the examples of FIG. 1C, aswell as FIG. 10A through FIG. 11B, FIG. 11C illustrates generallyfloatation table 2200. Additionally shown in the illustrative example ofFIG. 11C are first region 2201, printing region 2202, and second region2203. According to various embodiments of printing system 504C of FIG.11C, first region 2201 can be an input region, and second region 2203can be an output region. For various embodiments of printing system 504Cof FIG. 11C, first region 2201 can be both an input and an outputregion. Function referred to in association with regions 2201, 2202, and2203, such as input, printing, and output for illustration only. Suchregions can be used for other processing steps, such as conveyance of asubstrate, or support of a substrate such as during one or more ofholding, drying, or thermal treatment of the substrate in one or moreother modules. In the illustration of FIG. 11C, a first blower 3284A isconfigured to provide pressurized gas in one or more of the input oroutput regions 2201 or 2203 of a floatation table apparatus. Suchpressurized gas can be temperature controlled such as using a firstchiller 142A coupled to a first heat exchanger 1502A. Such pressurizedgas can be filtered using a first filter 1503A. A temperature monitor8701A can be coupled to the first chiller 142 (or other temperaturecontroller).

Similarly, as depicted in FIG. 11C, a second blower 3284B can be coupledto the printing region 2202 of the floatation table. A separate chiller142B can be coupled to a loop including a second heat exchanger 1502Band a second filter 1503B. A second temperature monitor 8701B can beused to provide independent regulation of the temperature of pressurizedgas provided by the second blower 3284B. In this illustrative example,as previously described herein for FIG. 1C, first and second regions2201 and 2203 can be supplied with positive pressure, while printingregion 2202 can include use of a combination of positive pressure andvacuum control to provide precise control over the substrate position.For example, using such a combination of positive pressure and vacuumcontrol, the substrate can be exclusively controlled using the floatinggas cushion provided by gas enclosure system 504C in the zone defined bythe printing region 2202. The vacuum can be established by a thirdblower 3290, such as also provided at least a portion of the make-up gasfor the first and second blowers 3284A or 3284B within the blowerhousing 3282.

FIG. 12 depicts a perspective view of OLED printing tool 4000 accordingto various embodiments of the present teachings, which can include firstmodule 4400, printing module 4500, and second module 4600. Variousmodules, such as first module 4400 can have first transfer chamber 4410,which can have a gate, such as gate 4412, for each side of firsttransfer chamber 4410 to accommodate various chambers having a specifiedfunction. As depicted in FIG. 12 first transfer chamber 4410 can have aload lock gate (not shown) for integration of first load lock chamber4450 with first transfer chamber 4410, as well as a buffer gate (notshown) for integration of first buffer chamber 4460 with first transferchamber 4410. Gate 4412 of first transfer chamber 4410 can be used for achamber or unit that can be movable, such as, but not limited by, a loadlock chamber. Observation windows, such as observation windows 4402 and4404 of first transfer chamber 4410, as well as observation window 4406of first buffer chamber 4460, can be provided for an end user to, forexample, monitor a process. Printing module 4500 can include gasenclosure assembly 4510, which can have first panel assembly 4520,printing system enclosure assembly 4540, and second panel assembly 4560.Similar to gas enclosure assembly 1000 of FIG. 1B, gas enclosureassembly 4510 can house various embodiments of a printing system. Secondmodule 4600 can include second transfer chamber 4610, which can have agate, such as gate 4612, for each side of second transfer chamber 4610to accommodate various chambers having a specified function. As depictedin FIG. 12 second transfer chamber 4610 can have a load lock gate (notshown) for integration of second load lock chamber 4650 with secondtransfer chamber 4610, as well as a buffer gate (not shown) forintegration of second buffer chamber 4660 with second transfer chamber4610. Gate 4612 of second transfer chamber 4610 can be used for achamber or unit that can be movable, such as, but not limited by, a loadlock chamber. Observation windows, such as observation windows 4602 and4604 of second transfer chamber 4610, can be provided for an end userto, for example, monitor a process.

First load lock chamber 4450 and second load lock chamber 4650 can beaffixably associated with first transfer chamber 4410 and secondtransfer chamber 4610, respectively or can be movable, such as on wheelsor on a track assembly, so that they can be readily positioned for useproximal a chamber. A load lock chamber can be mounted to a supportstructure and can have at least two gates. For example first load lockchamber 4450 can be supported by first support structure 4454 and canhave first gate 4452, as well as a second gate (not shown) that canallow fluid communication with first transfer module 4410. Similarly,second load lock chamber 4650 can be supported by second supportstructure 4654 and can have second gate 4652, as well as a first gate(not shown) that can allow fluid communication with second transfermodule 4610.

As previously discussed herein, various embodiments of a gas enclosuresystem can have an auxiliary enclosure that can be constructed as asealable section of gas enclosure assembly. According to systems andmethods of the present teachings, an auxiliary enclosure can be sealableisolated from a printing system enclosure, and can be opened to anenvironment external a gas enclosure assembly without exposing aprinting system enclosure to the external environment. Such physicalisolation of an auxiliary enclosure to perform, for example, but notlimited by, various printhead management procedures, can be done toeliminate or minimize the exposure of a printing system enclosure tocontamination, such as air and water vapor and various organic vapors,as well as particulate contamination. Various printhead managementprocedures that can include measurement and maintenance procedures on aprinthead assembly can be done with little or no interruption of aprinting process, thereby minimizing or eliminating gas enclosure systemdowntime.

For example, as depicted in FIG. 13A through FIG. 13D, gas enclosuresystem 505 can have first tunnel enclosure section 1200, which can haveinlet gate 1242 for receiving a substrate, and bridge enclosure section1300, as well as auxiliary enclosure 1330, which can be sealablyisolated from the remaining volume of gas enclosure system 505. Aspreviously discussed herein for FIG. 3A and FIG. 3B, purified inert gasfrom a purification system, such as purification system 3130 of FIG. 8and FIG. 9, can circulate into gas enclosure system 505, for example,into bridge enclosure section 1300, from a gas purification inlet line,such as gas purification inlet line 3133 of FIG. 3A, FIG. 3B, FIG. 6,FIG. 8 and FIG. 9. As depicted In FIG. 13A, during, for example, aprinting procedure, inert gas can be circulated to a gas purificationsystem, such as purification system 3130 of FIG. 8 and FIG. 9, from agas purification outlet line, such as gas purification outlet line 3131Aof FIG. 3A. As depicted in FIG. 13B, during, for example, a maintenanceprocedure, auxiliary enclosure 1330 can be opened to the externalenvironment for access after being sealably isolated from the remainingvolume of gas enclosure system 505. During such a procedure, inert gascan be circulated to a gas purification system, such as purificationsystem 3130 of FIG. 8 and FIG. 9, from a gas purification outlet line,such as gas purification outlet line 3131B of FIG. 3B. Purified inertgas can be returned to gas enclosure system 505 from a gas purificationsystem, such as purification system 3130 of FIG. 8 and FIG. 9, from agas purification inlet line, such as gas purification inlet line 3133 ofFIG. 3A, FIG. 3B, FIG. 6, FIG. 8 and FIG. 9.

As depicted in FIG. 13C, after a procedure, such as a maintenanceprocedure, has been completed, auxiliary enclosure 1330 can be isolatedfrom the external environment. During, for example, a recovery procedurefor auxiliary enclosure 1330 after it has been opened to the externalenvironment for access, an inert purge gas from an inert gas source,such as inert gas source 3201 of FIG. 10A and FIG. 11A, can becirculated through auxiliary enclosure 1330 while it is still sealablyisolated from the remaining volume of gas enclosure system 505. Duringsuch a procedure, inert gas can be circulated to a gas purificationsystem, such as purification system 3130 of FIG. 8 and FIG. 9, from agas purification outlet line, such as gas purification outlet line 3131Bof FIG. 3B. Purified inert gas can be returned to gas enclosure system505 from a gas purification system, such as purification system 3130 ofFIG. 8 and FIG. 9, from a gas purification inlet line, such as gaspurification inlet line 3133 of FIG. 3A, FIG. 3B, FIG. 8 and FIG. 9.Finally, as depicted in FIG. 13D, once auxiliary enclosure 1330 has beenfully recovered, as depicted in gas enclosure system 505 can be returnedto the same flow communication path as described for FIG. 13A.

It should be understood that various alternatives to the embodiments ofthe disclosure described herein may be employed in practicing thedisclosure. For example, while vastly different arts such as chemistry,biotechnology, high technology and pharmaceutical arts may benefit fromthe present teachings. OLED printing is used to exemplify the utility ofvarious embodiments of a gas enclosure system according to the presentteachings. Various embodiments of a gas enclosure system that may housean OLED printing system can provide features such as, but not limitedby, a controlled, low-particle environment in a contoured enclosurevolume, and ready access from the exterior to the interior duringprocessing, as well as during maintenance. Such features of variousembodiments of a gas enclosure system may have an impact onfunctionality, such as, but not limited by, structural integrityproviding ease of maintaining low levels of reactive species duringprocessing, as well as rapid enclosure-volume turnover minimizingdowntime during maintenance cycles. As such, various features andspecifications providing utility for OLED panel printing may alsoprovide benefit to a variety of technology areas.

While embodiments of the present disclosure have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the disclosure. It is intended thatthe following claims define the scope of the disclosure and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

1. (canceled)
 2. A method for processing a substrate, the methodcomprising: maintaining a controlled gas environment within a gasenclosure; circulating gas within a tunnel structure positioned withinthe gas enclosure so as to provide a flow of gas across a substratesupported by a substrate support apparatus disposed within the tunnelstructure; and circulating gas within a bridge enclosure structurepositioned within the gas enclosure, the bridge enclosure structureenclosing a printing system bridge; and depositing ink onto a surface ofthe substrate from at least one printhead assembly mounted to theprinting system bridge, the depositing occurring during circulating gaswithin the tunnel structure and the bridge enclosure structure.
 3. Themethod of claim 2, wherein circulating gas within the bridge enclosurestructure comprises directing a portion of the gas from the tunnelstructure to the bridge enclosure structure.
 4. The method of claim 2,further comprising circulating gas within a service bundle housing andpast at least one of an optical, electrical, mechanical, and fluidiccable coupled to the at least one printhead assembly and routed throughthe service bundle housing.
 5. The method of claim 2, further comprisingflowing a portion of the gas from the gas enclosure through a gaspurification loop and back to the gas enclosure.
 6. The method of claim5, wherein flowing the portion of the gas through the gas purificationloop removes solvent from the portion of the gas.
 7. The method of claim2, further comprising cooling the gas circulated through the bridgeenclosure structure and/or through the tunnel structure.
 8. The methodof claim 2, further comprising flowing a portion of the gas from the gasenclosure through a gas pressurization component and back to the gasenclosure to maintain a predetermined pressure within the gas enclosure.9. The method of claim 2, further comprising filtering particulatematter from gas circulated through the tunnel structure.
 10. The methodof claim 2, further comprising filtering particulate matter from gascirculated through the bridge enclosure section.
 11. The method of claim2, further comprising moving the printhead along the bridge whiledepositing ink on the surface of the substrate.
 12. The method of claim11, further comprising moving the substrate in a direction perpendicularto a direction of movement of the printhead along the bridge whiledepositing ink on the surface of the substrate.
 13. The method of claim2, further comprising moving the substrate while depositing ink on thesurface of the substrate, wherein a direction of the flow of gas acrossthe substrate is perpendicular to a direction of the moving of thesubstrate.
 14. The method of claim 2, further comprising supporting thesubstrate via floatation using a floatation table while depositing theink.
 15. The method of claim 2, wherein depositing the ink comprisesdepositing an ink comprising an organic material used to form at leastone layer of an organic light-emitting diode stack.
 16. The method ofclaim 2, wherein depositing the ink comprises depositing an inkcomprising an organic material used to form an encapsulation layer of anorganic light emitting diode display.
 17. The method of claim 2, whereinmaintaining the controlled environment in the gas enclosure comprisesmaintaining a non-reactive gas environment in the gas enclosure.
 18. Themethod of claim 17, wherein the non-reactive gas environment ismaintained using nitrogen gas.
 19. The method of claim 2, whereinmaintaining the controlled environment in the gas enclosure comprisesmaintaining at least one of water vapor, solvent vapor, ozone, andoxygen below a specified limit.
 20. The method of claim 2, wherein theflow of gas across the substrate is substantially laminar.
 21. Themethod of claim 2, wherein maintaining the controlled environment in thegas enclosure comprises maintaining the environment to meet aparticulate contamination specification.
 22. The method of claim 21,wherein the particulate contamination specification is an on-substratedeposition rate specification of less than or equal to about 100particles per square meter of substrate per minute for particles greaterthan or equal to 2 μm in size.